To accomplish this, you would need to use discrete codes for the specific inputs. Unfortunately, I don't have discrete codes available for specific inputs and I haven't seen them available in recent years.
I recently purchased a couple of Sony RM-VLZ620 universal remote controls to operate my HDTVs and associated kit of DVD, Roku, DVR, etc. The URC has feature that allows one to program sequences of predefined key presses to operate multiple devices. In the basement with my Sharp HDTV, this permits me to press a single key and have the TV, DVR, and A/V system turn on, and then have the A/V system select the DVR as its input source. This works because source inputs on the A/V system are individually selectable (HDMI1, VIDEO1, VIDEO2, etc.).
In the family room, however, where I don't have an A/V system and where feeds go straight into the TV, I haven't been able to get this scheme to work, because the source select on my Samsung LN40C630 is a toggle, i.e., pressing SOURCE advances the input from its current setting (whatever that is), to whatever the next connected input is, which apparently means that I can't select an individual input, nor can I count on starting at a specific place in the input list (e.g., always start at PC, then advance two places in the list to DVR, or similar).
Does anyone know of a way that I can accomplish my aim, which is to define the sequence of keystrokes necessary to select a specific source input on this television?