Is it possible to have smsd send arbitrary AT commands to the modem?

Sometimes I want to forward voice calls to a different number using the GSM AT command "*21*18885551212#" and cancel it using "##21#".

Right now, I'm stopping smsd, opening a connection to the modem using a terminal emulator (minicom, tip, cu, or whatever), running the commands by hand, exiting the terminal emulator, and then restarting smsd.

It would be awesome if I could just tell smsd to do that for me.

If this feature isn't available, is it a reasonable feature request?