RPC via telephone

i want to be able to send commands to my computer via a telephone call.  how do i do this?

example:
*dial into computer*
PC: press 1 to defrag, press 2 to run database scripts, press 3 to FORMAT HARD DRIVE.

You may need some kind of CSTA-enabled automated attendant, that provides the digits tones over CSTA. Not all telephone systems support this, but it's possible the Siemens HiPath does.