SUBSTITUTE

Swaps an instance of text in a string with new text. 

Syntax

SUBSTITUTE(text-expression,old-text,new-text,instance)

Arguments

text-expression	Text or cell reference to evaluate.
old-text	The text to swap.
new-text	The text to insert.
instance	The instance of the old-text to swap.  Must be greater than 0, if omitted the function assumes (the first instance of the text).

Example

SUBSTITUTE("The old dog is old","old","blue",2) returns "The old dog is blue"