Yes, Aravind is correct, but *XDIM_MEMBERSET is also fine:
*SELECT(%VAR%,"ID","ACCOUNT", "[IC] = "Y"")
*XDIM_MEMBERSET ACCOUNT = %VAR%
...
*WHEN ACCOUNT
*IS *
*REC(EXPRESSION=%VALUE%)
*ENDWHEN
Vadim
P.S. And the original error is absolutely clear - you are trying to write result to account "Y"