Updating cells

I have a workbook with merged cells with code that increases row height as
needed according to size of the string. I created a macro that essentially
goes to each such cell and hits F2 enter causing the cell to update and
readjust to the new string size. But since the macro uses Activecell.Formula,
inserting the formula, if I change the formula, I have to remember to change
it in the code, too.
Is there any way to accomplish updating the formula results without using
Activecell.Formula in VBA?
Thanks

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Scafidel
Lafayette, Louisiana