Google voice back door dialer

Can anyone tell me how to program an access number into my Andriod? I want to set up my Android so when I select a contact number to dial, it calls my own access number, enters in a pause and menu selection then dials the contacts's number followed by a #. I realize I couild put all the digits in each contact number (I think) but that of course would be combersome. I want to do this to dial my Google voice mail number (which never changes) and dial via the menu instead of the normal Google dial method that uses a variable access number (Friends and Family issue). Any suggestions?