sort by matching content

So I am trying to add tags that will describe the content within the document so I know that I hav a lot of contracts that contain the following words on the first or second page:
This ... Agreement
the ... could be License, Lease, Consulting etc...
My problem is that I cannot figure out how to set out a parameter - perhaps using "contents>contain match" and some sort of custom text... that will look only at documents that have either a phrase "this agreement" or "this ... agreement" where ... is a wildcard that can't be more than 1 or 2 words...
I need some help here!
Thanks in advance...
This ... Agreement
the ... could be License, Lease, Consulting etc...
My problem is that I cannot figure out how to set out a parameter - perhaps using "contents>contain match" and some sort of custom text... that will look only at documents that have either a phrase "this agreement" or "this ... agreement" where ... is a wildcard that can't be more than 1 or 2 words...
I need some help here!
Thanks in advance...