Substitutes new_text for old_text in a text string. Use SUBSTITUTE when you want to replace specific text in a text string; use REPLACE when you want to replace any text that occurs in a specific location in a text string.
Syntax
SUBSTITUTE(text,old_text,new_text,instance_num)
Text is the text or the reference to a cell containing text for which you want to substitute characters.
Old_text is the text you want to replace.
New_text is the text you want to replace old_text with.
Instance_num specifies which occurrence of old_text you want to replace with new_text. If you specify instance_num, only that instance of old_text is replaced. Otherwise, every occurrence of old_text in text is changed to new_text.
Examples
SUBSTITUTE("Sales Data", "Sales", "Cost") equals "Cost Data"
SUBSTITUTE("Quarter 1, 1991", "1", "2", 1) equals "Quarter 2, 1991"
SUBSTITUTE("Quarter 1, 1991", "1", "2", 3) equals "Quarter 1, 1992"
To replace every occurrence of the text constant named Separator in the cell named CellCont2 with square brackets:
SUBSTITUTE(CellCont2, Separator, "] [")