Is there anyway to run find and replace on a selection in the workbooks?

Here's what I'm trying to do:

I have some machining for in wall brackets on a floating shelf. I have the product set up with prompts so that I can enter the field measurements and bracket specs to control those pockets. I was just about to pat myself on the back, when I realized that I was machining non-miterfold parts and these are going to be miterfold shelves. The mierfold blanks need different parameters, which isn't a huge deal. Now, since I want to keep what I have so it can be used for miterfold or not, I copied all of my hidden prompts doing my math and prepended "Miterfold" on them. Now I need to go through all of the formulas and change "Pocket_..." to "Miterfold_Pocket_...". Find and replace seems the obvious solution, but I don't see a way to limit to a selection of cells. Is there a way to do that?