The reason that the Find is looking in all cells, and not just column C, is that is what is specified. The code specifies
and Cells is a reference to the entire worksheet. You have used
but then the code never actually takes advantage of that With. To do that you want something like this:
The .Find means "Do a find on the range I have specified in my With statement."
However, that doesn't solve your problem
I just am trying to do a little education there. The bigger problem is that a Find can only find a string, it cannot find cells that fail to match a string. That would have to be done as an explicit loop. I have suggested one solution here. You will also note that I declare all variables, which I highly recommend (along with Option Explicit, which is automatically provided in new modules if you set Tools, Options, Require Variable Declaration).
I have tested this code on your file and I believe it does what you want:
Bookmarks