How does one go about recognizing a dial tone, busy signal and etc. when using a modem to place a call?

Our Scout Troop has a calling committee that has to place numerous calls each week and it is becoming a burden to those involved. I thought I would give it a try in VBA to dial a telephone number, recognize that someone picked-up, busy signal or answering machine. Either way eventually play a file reminding them of the event....and move on to the next telephone number.

The software packages available are too expensive for our Troop budget.

Any advice would be appreciated.