oh ok..I got it.
So, for this purpose, you have to probably use a Global Internal table (in global data section of your activity/condition function group) to save the Batch Guid (I_EAI-EVENT_MSG-HDR-BATCH_GUID), Evt ID and say a "Already Processed" flag.
Make an entry in this internal table during the 1st run of the same Batch, if the total count is > 25.
Thanks,
Deb