Hi Jon.
First you must create filter. If you used Contest window and had there unique contest name then the easiest filter is to select "Qso list/filter/Contest filter". Otherwise you use filter by date/band/mode.

You need filter even when you had a new log for this contest alone.

When filter is set open "Qso list/file/export/cabrillo"
Set path and name for cabrillo file and give name for contest.
Usually other settigs are ok down to exchange part.
I think first exchange for you is stx_string having your state.
Second exchange depends how you stored receved message. I would have used "Contest/MSG r" because there were serial numbers and states mixed.
In that case second exchange would be "srx_string"

Then use export button and once done you see button "open exported file" press that and look that cabrillo file format is what this contest needs. You must have set "preferences/external viewers/text file" column to have path and name of your ptogram to open text files to make button work.
You can repeat export to same file so many times that result meets the cabrollo format of this contest.

As Cqrlog is not a contest program with ready-made contest layers you must use some imagination and do some work to get results exported.
How ever, once you have done it few times you see that it is not so difficult.
See also "Help" about contest and exporting.