In order to control X10 with any remote, you need some sort of tranceiver unit. You have 2 options. The first is an RF-2-X10 transceiver, but that would liit you to using an X10 RF remote (the 15-2117 wouldn't work for this purpose). The second option is to get an IR-2-X10 unit (known as an IR543 box) which will convert IR signals into X10 signals. Which this box, you can use HOME/0167 in the 15-2104 to work your X10 dimmer. You can get an IR543 from Home Automation Net for $20, here's a link...
[Link: hifi-remote.com]