Check out this article that I've written up recently - Getting Started with the MBSDK (Example Scripts Included) - that should help you out.
Essentially, you can write your own BNF queries (so that you define your "scanned recently" however you want) and get a set of data back.
Something like the following for instance:
"COMPUTER"."Last Updated by Inventory Server" > "GetDate()-30"
... which you can throw at the MBSDK as a query, and then get the resulting data-set back.