Tricking a CD Player

Has anyone had any luck in "tricking" your sony disc player into thinking that your computer's audio output is actually a second disc player? I have one CDP260 and my other source is the MP3's on my computer. I want to be able to have both of these sources enter my pre-amp through the same inputs (and thus play off of the same source selection of "CD". I tried hooking the audio out from my computer to the "Second CD Player" RCA inputs on the back of my disk player, but somehow that does not work (I assume it is because the disk player does not recognize that there is another input so it does not route the signal).

Any thoughts on making this work? Don Haberek gave me his solution in my last post (thanks Don) of routing everything (including the CD player) through my computer using the Tape inputs / outputs on my preamp. This does not work for me as my preamp does not support remote control of the tape monitor function so it locks me into one source unless I go downstairs and mnually switch it.

What about just putting a Y at the preamp level and applying both inputs there? Will that do any damage to my preamp?