Lisp Help: Search text in Viewport and update title block

I'm looking for a lisp routine that is capable of searching the content of my view ports for the highest numeric attribute value with a specific tag. For example we have blocks set up with revision numbers, and adjacent to those revision numbers are two attribute tags; one for versioning, and one for si/cn number. The revision triangles are named rev1-rev10, each has a specific colour, and each is placed next to a revision cloud with the corresponding color via lisp; the lisp allows you to draw the cloud and automatically inserts the revision triangle when the rev cloud closes.

Essentially what we are doing here is devising a method of tracking changes between major architectural revisions. Everything revised AFTER the submission, R2 for example, will be tagged with this attribute block allowing us to tag it R2-V2.2, it's mainly for interoffice use. We have a slot in our title block to record the latest version of that sheet, but it can be cumbersome to keep it all up to date.

What I would like to do is get my hands on a lisp routine that would search each viewport and update my title blocks with the appropriate version number (I.E. the highest version number on that given page) to ensure each page is up to date.

Any ideas?

P.S. I'm just scratching the surface when it comes to understanding lisp, the ones I write are laughable compared to the ones I've obtained online.

Thanks all.