What exactly are you trying to achieve, and how much manual work are you prepared to put into it?
A current solution requiring manual work would be as follows:
* Before starting a playback session, use the inbuilt tag copy function to copy all current playcounts to a user field. (If you're only using a subset of files, this will obviously be quicker. A few thousand files would be workable, more I don't know)
* After ending the playback session, copy all playcounts back.
There's *probably* a way to script the copying process and zone, but I think that would probably require using MCWS to launch the playback & change the zone.
MrChriz knows a lot more about scripting than I do, so with a little luck he may drop in
We may be able to come up with a better solution if you let us know what you're after though. Depending on what you want, this *may* work:
If the files you do not wish the playcount incremented for are uniquely identifiable (Genre, artist etc.), then a calculated field keyed off this is doable, but we really need the details to advise properly.
-Leezer-