Originally Posted by David Price 
I just want to say that I just followed these steps on my 700P and it works like a charm!
The only downside is that the default dialer app won't do a hard pause, so if your call takes longer than expected to connect, it might dial the extra digits before the remote system is ready to accept them.
You might want to check out
TakePhone, mentioned earlier in this thread. It offers hard pause (tap a button on the screen to dial extra digits), as well as a host of other features like dial by photo, calling cards, location-based dialing, etc.
The developer has excellent support as well.