I remember years ago my friend and i were playing command and conquer red alert and there was a mode were we put the others phone number and the game would dial up and connect. What was this called? and where can i find resource to program for this?
Have a look at TAPI (Telephony API). In Windows world there is a set of APIs in the OS for this (http://msdn.microsoft.com/en-us/library/ms737219(VS.85).aspx). The AT command set (Hayes commands) can also be used without TAPI in Windows if you treat your Modem as a COM port and send AT commands to that COM port (that's what actually TAPI does) but it isolates you from their different variants and also running initialization and other commands in a particular order.