I always created 2 Short codes.

#2XX
Voicemail Transfer
"#"2N

*2XX
Dial Direct
N

Obviously those are for 3 digit extensions that begin with a 2...but you get the gist of it.
That allowed me to have a manual for customer that said, press TRANSFER, POUND 201, to transfer directly to voicemail...

And now user can dal STAR ext number, or STAR and BLF button, to go direct to intercom.