You're not missing anything, but without discrete codes, which are probably not available for your model TV, you will have to find another way to do this.

The easiest way to make the macro is to determine if your TV will go back to the TV input by pressing the channel up or down button, or even any channel number.

If it does, make a macro with one of these commands to get you back to a standard start point, which is the tv input, and then insert the necessary number of commands to get you to the input you want.