Sony have used both device 11 and 186 for VCR codes. I'm going to assume that you are using setup code Video 20032 (would be 0032 on gray OK/Select remotes), and assigning to the AUX device mode.

Try the following EFCs for Execute:
00094 (I expect this one to work)
00202 (although this one will probably also act as play if you're not in a menu.

Actually, the OK/Select button has 00094 assigned to it at the factory, but the remote is setup for Cable Channel Lock, which means that all digits, Ch+/-, and OK/Select are routed to the cable box regardless of device mode. You can shut off Cable Channel Lock, but in fact it is normally a good idea, and instead assigning the EFC to OK/Select will override the Channel Lock for that button.