First set up your KP to look like a BCR2000 to Live. This will allow you to control up to 5 parameters (X, Y, fx depth, touch and mute on the KP) from the KP on any rack you select with the mouse. Just set the KP to send CC 1-5 and it will automatically control the first 5 dials on any selected rack as soon as you enable the KP as a BCR2000 in the prefs.
More details found here:
http://www.ableton.com/forum/viewtopic.php?t=53721
That is nice, but you still need the mouse to actually select the rack you want to control. Wouldn't it be nice if you could select which rack you like to control with the 8 preset buttons on the KP?
Well that is possible, with a bit of fiddling. The thing is, you can't select racks or other devices remotely, only with the mouse. Stupid, eh?
Or you can use the alt-arrow keyboard command. So if you select a track, then alt-uparrow a couple of times (to "reset" where selection where previously) follow by a couple of alt-downarrows, you will have selected the first rack/device on that track. If you follow by a single alt-rightarrow you will select the next rack/device etc.
But we don't want to use the keyboard, we want to use the preset buttons on the KP. They can only send Program Changes.
So, to achieve this we use Boomes Midi Translator. Map the appropriate Program Change to a letter followed by a lot of alt-uparrows followed by a lot of alt-downarrows (and optional alt-rightarrows). Map that letter in Live to a track selection. Now when you press the preset button, that track will be selected and the first rack on that track will also be selected. This means that the KP will automatically control parameters 1-5 on the rack. Press another preset button and you will control another rack.
Cool eh?