Replace specific part of formula in a cell through VBA

I have a formula in a cell and I want to use VBA to replace specific parts of that formula.

For instance:

=IF($C$55>(M26*$N$25),0,(M26*$N$25)-$C$55)

I want the Macro to find $C$55 in both instances and replace it with another cell of my choosing.

I have the replacement cell set using VBA. I want to replace it with whatever cell is Monthrange.offset(6,0).address.

So if the cell MonthRange.offset(6,0).address is F55 then I want $C$55 to be replaced with $F$55

Is there a quick and easy way to do this?

Thanks in advance for your help.