Screen 1 Miscellaneous Info has an otherwise unused Custom Filter.  You could use this for that purpose. e.g. Enter IPIN in that input, then create a custom Filter in the left column by doing what I have in the image.

You might be able to use this same approach to create a report.  What I am showing just gives you those clients filtered on your client screen.

I'm looking for the same thing.  Doesn't using the Custom Filter option mean that you have to have something input in the Custom Filter box (on Screen 1 just about Firm Number) in each specific client?  Or is there another way to create a custom filter?

I don't see the desired  field in the options to pick for filters/reports. Yes, you would need to add this for each client. Go to the Idea Exchange and ask for that field to be added.