This is a long shot, but I have a Sony VCR with a
jog shuttle on the console, but none on the
remote, and I did an exhaustive search for
advanced codes, and found, among other things,
the codes for the jog shuttle:

Jog/Shuttle dial clockwise = 104
Jog/Shuttle dial counterclockwise = 100

It's a long shot, but Sony's better than most
about using the same advanced codes from device
to device, so it might be worth a shot. Let me
know if it works.

I'll say this: It's very doubtful that a function
existed that cannot be remote activated somehow.

-=Ingenious=-