AT Commands need help!

Hi, Is there an AT command that would identify the number of a sender(sms)?

In what?

Have you thought about maybe RTFM?

I "think" you're talking about a GSM/GPRS modem. If so, what brand. I know the SIMCom SIM900 has a manual for AT commands. Google SIM900 AT Command manual. Go to page 70/71. There are more than one command involved. p.s. It would help others to help you if you gave more detail in the question.