Chars in macro

I have a macro created to do some vast form changes.
What I now attempting to do is a find and replace.
I need to find all of the (%%C) which is the Dia. symbol out of AutoCad
and replace all occurences with a =CHAR(216) which is Excel's symbol for Dia.
The items will be in a format with text in front and maybe in the back of a string. EXAMPLE 10"%%C (which indicates a 10" round object)
should change to 10'' Ø

Any and all help would be appreciated.
I have rec'd much help from people in ths forum that has taken there time
to assist in there problems and I am very grateful to them.

Thank You

63 Falcon