In the MsComm thing, there is an event that happens when the modem rings. In most modems, there is also a ring count register (S1).

When you get the comEvRing event, just look at the ring counter in the modem if you wanna have it ring a couple times first, or just pick it up there.

Look up AT modem commands to control the modem. It's easy. (ATH1 brings the phone off the hook).
Written using the Dvorak keyboard layout.