On Timer - channel selection

I use my KDL-40V3000 with a cable box, attached via an HDMI cable. When I turn the TV on manually, it turns on to the HDMI-2 input, which is where my cable box is and it's where I leave the TV when I turn it off.
Now, I would like to use the on-timer. When I set the on-timer, I am forced to choose a channel. This is a meaningless selection, because I use the cable box and, therefore, I don't even have my channels set up. The result is that when I use the timer to turn the TV on, it automatically goes to channel 2 (the default channel for the on-timer settings).  What I want is the TV to turn on with the "channel" as the HDMI-2 input (which is where my box is attached).  I cannot change the on-timer channel to HDMI or HMDI-2 (or anything besides channel 2, since I don't have any channels set up).
How do I use the on timer to turn my TV on in HDMI-2 mode?