Logical by date problem

HI I have a subfile program looking at EDI data, masses of it. I built a
logical file, but the data load was too large. I was told to Select on the
date starting from this past May so of course it loads straight away. I
was told to build a small program to mark the EDI records so that I will
only be loading 2 months or so. Now there must be a better way to do this?

I am thinking of embedded SQL in the RPG program. Is this the preferred
method?

Thanks,
Steve