Has anyone tried to use "Pause" while registering a phone number ?

I frequently dial into a conference call. My cell phone is able to dial the phone number and passcode as a single speed dial. On the cell phone, the number is set up as "888-nnn-nnnn<pause><pause>xxxxxx#" where the last part is the passcode.

When I set up the number in the TCH in the same way, it never dials the passcode automatically. I have tried with different number of <pause>s without any luck.

I know I could use "Speed Tone" for the passcode, but that would take pressing more buttons to call