SUBSTITUTE Function
From Planfix
This function substitutes the value of the "new_text" argument in place of the value of the "old_text" argument in a string. The SUBSTITUTE function is used when you need to replace a specific part of a string.
Format:
- SUBSTITUTE(text;old_text;new_text)
Examples:
SUBSTITUTE(A;"sales";"prices")
SUBSTITUTE(//Template:Task.String field//;"what";"where")