Complicated Find - Replace

I don't know about anyone else, but I'm struggling to understand what you want to do and how it is determined. Can you expand on what you're doing?

No Problem.

I currently have a list of parts with numbers that correspond to work centers stretched out horizontally after the part number. I would like a macro that will search these work center numbers and add a new number below the old.

An example is how I have 10 with 910 below or 5 with 400 below. I did that by hand, but I have thousands of parts to work through and would like for it to be accomplished automatically.

So do you have a list of part numbers and numbers that go below them? If so, could you not use a LOOKUP formula?

I do have a list of work centers and the new work centers I would like below. However the list is horizontal and not vertical, so a LOOKUP doesn't work, that's why I was trying to use FIND REPLACE.

There is an HLOOKUP formula...