Dial a number through the modem and pick up the line (from the telephone that is connected to the modem) before timer reaches 0.

You can use command line arguments:
mdialer com-port(the modem is connected) number of phone to dial seconds to keep modem off-hook and auto .
mdialer.exe 5  12345 12 auto
This means open modem on comport 5 dial the number 12345 and wait 12 seconds after dialing.

Get it here mDialer.exe (33k)

You may need the Visual Basic 6 runtime files.
Get them from Microsoft