Using DTMF With My Modem

:) Hi everybody...
I would like to know if there is any way to send any DTMF Signal (through my mobile phone for example) and with my PC ,on power of course,recieve them and if its a particular string to do something...In fact i would like to connect my pc to the inet making just one call to my home number an when the modem recieve the call with one DTMF tone make a particular action...
Anyway if there is no way through DTMF,is there another???
Thnx In Advance :)
Manolis