diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 8e64bb1d..13617b77 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -9,7 +9,7 @@ v3.2.1
 - Add support for JSON strings to the `DICT` replacement. Example: [DICT:{"key": true}]
 - Add `REPLACE` replacement, to replace a substring with another. Example: [REPLACE:[CONTEXT:some_url]::https::http]
 - Add `TITLE` replacement, to apply Python's title() function. Example: [TITLE:the title]
-
+- Add `ROUND` replacement, float number to a string with the expected decimals. Example: [ROUND:3.3333::2]
 
 v3.2.0
 ------
diff --git a/toolium/test/utils/test_dataset_map_param_context.py b/toolium/test/utils/test_dataset_map_param_context.py
index 449056e3..292c1ffd 100644
--- a/toolium/test/utils/test_dataset_map_param_context.py
+++ b/toolium/test/utils/test_dataset_map_param_context.py
@@ -456,6 +456,33 @@ class Context(object):
     dataset.behave_context = context
     assert map_param("[CONTEXT:list.cmsScrollableActions.-1.id]") == 'ask-for-negative'
 
+def test_a_context_param_list_incorrect_negative_index():
+    """
+    Verification of a list with a correct negative index (In bounds) as CONTEXT
+    """
+    class Context(object):
+        pass
+    context = Context()
+
+    context.list = {
+        'cmsScrollableActions': [
+            {
+                'id': 'ask-for-duplicate',
+                'text': 'QA duplica'
+            },
+            {
+                'id': 'ask-for-qa',
+                'text': 'QA no duplica'
+            },
+            {
+                'id': 'ask-for-negative',
+                'text': 'QA negative index'
+            }
+        ]
+    }
+    dataset.behave_context = context
+    assert map_param("[CONTEXT:list.cmsScrollableActions.-5.id]")
+    
 
 def test_a_context_param_list_oob_index():
     """
diff --git a/toolium/test/utils/test_dataset_replace_param.py b/toolium/test/utils/test_dataset_replace_param.py
index 0ba7d065..bec1eb64 100644
--- a/toolium/test/utils/test_dataset_replace_param.py
+++ b/toolium/test/utils/test_dataset_replace_param.py
@@ -375,6 +375,13 @@ def test_replace_param_dict():
     assert param == {'a': 'test1', 'b': 'test2', 'c': 'test3'}
 
 
+def test_replace_param_dict_json_format():
+    param = replace_param('[DICT:{"key": "value", "key_2": true}]')
+    assert param == '{"key": "value", "key_2": true}'
+    param = replace_param('[DICT:{"key": "value", "key_2": null}]')
+    assert param == '{"key": "value", "key_2": null}'
+
+
 def test_replace_param_upper():
     param = replace_param('[UPPER:test]')
     assert param == 'TEST'
@@ -454,3 +461,10 @@ def test_replace_param_title():
     assert param == "Holahola"
     param = replace_param('[TITLE:hOlA]')
     assert param == "HOlA"
+
+
+def test_replace_param_round():
+    param = replace_param('[ROUND:7.5::2]')
+    assert param == "7.50"
+    param = replace_param('[ROUND:3.33333333::3]')
+    assert param == "3.333"
diff --git a/toolium/utils/dataset.py b/toolium/utils/dataset.py
index 0eafb24b..781eb687 100644
--- a/toolium/utils/dataset.py
+++ b/toolium/utils/dataset.py
@@ -84,6 +84,7 @@ def replace_param(param, language='es', infer_param_type=True):
         [STR:xxxx] Cast xxxx to a string
         [INT:xxxx] Cast xxxx to an int
         [FLOAT:xxxx] Cast xxxx to a float
+        [ROUND:xxxx::2] String float with the expected decimals
         [LIST:xxxx] Cast xxxx to a list
         [DICT:xxxx] Cast xxxx to a dict
         [UPPER:xxxx] Converts xxxx to upper case
@@ -228,24 +229,22 @@ def _get_random_phone_number():
 def _replace_param_transform_string(param):
     """
     Transform param value according to the specified prefix.
-    Available transformations: DICT, LIST, INT, FLOAT, STR, UPPER, LOWER, REPLACE, TITLE
+    Available transformations: DICT, LIST, INT, FLOAT, ROUND, STR, UPPER, LOWER, REPLACE, TITLE
 
     :param param: parameter value
     :return: tuple with replaced value and boolean to know if replacement has been done
     """
-    type_mapping_regex = r'\[(DICT|LIST|INT|FLOAT|STR|UPPER|LOWER|REPLACE|TITLE):([\w\W]*)\]'
+    type_mapping_regex = r'\[(DICT|LIST|INT|FLOAT|STR|UPPER|LOWER|REPLACE|TITLE|ROUND):([\w\W]*)\]'
     type_mapping_match_group = re.match(type_mapping_regex, param)
     new_param = param
     param_transformed = False
 
     if type_mapping_match_group:
         param_transformed = True
-        if type_mapping_match_group.group(1) in ['DICT', 'LIST', 'INT', 'FLOAT']:
-            if '::' in type_mapping_match_group.group() and 'FLOAT' in type_mapping_match_group.group():
-                params_to_replace = type_mapping_match_group.group(
-                    2).split('::')
-                float_formatted = "{:.2f}".format(round(float(params_to_replace[0]), int(params_to_replace[1])))
-                new_param = float_formatted
+        if type_mapping_match_group.group(1) in ['DICT', 'LIST', 'INT', 'FLOAT', 'ROUND']:
+            if '::' in type_mapping_match_group.group() and 'ROUND' in type_mapping_match_group.group():
+                params_to_replace = type_mapping_match_group.group(2).split('::')
+                new_param = f"{round(float(params_to_replace[0]), int(params_to_replace[1])):.{int(params_to_replace[1])}f}"
             elif type_mapping_match_group.group(1) == 'DICT':
                 try:
                     new_param = json.loads(type_mapping_match_group.group(2).strip())
@@ -646,7 +645,8 @@ def get_value_from_context(param, context):
         if isinstance(value, dict) and part in value:
             value = value[part]
         # evaluate if in an array, access is requested by index
-        elif isinstance(value, list) and part.lstrip('-+').isdigit() and int(part) < len(value):
+        elif isinstance(value, list) and part.lstrip('-+').isdigit() \
+                and int(part) < (len(value) + 1 if part.startswith("-") else len(value)):
             value = value[int(part)]
         # or by a key=value expression
         elif isinstance(value, list) and (element := _select_element_in_list(value, part)):