TV card with IR capability to change channels

Comcast is now requiring me to have a TV set top box even for basic cable. I have to assume they will encrypt all channels.

I have read the horror stories of trying to get a digital TV card to work with Comcast.

My question:
The set top box has an ir adapter which will receive signals from the remote control supplied by Comcast.

Which TV card manufacturers have a TV card supplied with an IR device to transmit codes to the Comcast set top box?

If the proper signal can be sent to the set top box to change channels then I don't need a digital TV card and can avoid the hassles of installing the special card from Comcast.