Touch 101: Editing Voice Mail Speed Dial?

[intelbank]

Another probably noobish question from me: If it's been asked before and answered - i haven't been able to located the thread, my apologies.

I've been trying to find a way to access the #1 speed dial button to add my pass code via #.... to my VoiceMail phone number, but can't seem to find a way to do that.
While that may seem trivial to many people, if i could then add a voice tag to dial my voice mail, i wouldn't have to type my pass code in - which would make it very handy while driving.
Anyone know how to get to edit the #1 speed dial/Voice mail?

Thanks,
IB