Mod wheel as Expression controller?

OK, I give up. How do I map Expression to the mod wheel on my Keystation controller? I've been trying to get it working but I really don't know how to go about it. Tried the track midi control thingy, which lets me assign the mod wheel to different stuff, but that way I get *both* Expression and modulation, plus that Expression does not get recorded. I want to remove Modulation from the mod wheel, so to speak, and have only Expression. What's the necessary steps to achieve this? Edit: and one second after I posted the thread, I realized it probably belongs in the Q&A section. Sorry 'bout that.

JS: midi_CC_mapper perhaps?

The CC mapper is acting on playback, it works fine as long you ignore the fact that actually CC#1 (mod wheel) gets recorded and the plugins sits in front of the VSTi. It will be translated to CC#11/43 again on playback. If you need to have the expression CCs recorded on the item (e.g. if you need to export the MIDI later), you can simply "apply FX to items as new take (MIDI)" after recording. The best way would be to reassign the wheel on the controller itself, which is often not possible (it isn't on my old Keystation 49, only the volume slider can be reassigned).

I dont know inside reaper, but using midiox is pretty easy.

Try midiConverter2 in the piz midi package. I use it to convert CC80 to Channel Pressure which is similar to what you want to do.

Thanks for the tip merdave, but that plug appears to work exactly like the JS one. I.e. it does not remove the modulation assignment from the mod wheel, it just adds Expression on top of it (the notes change their volume AND wobble), plus that it does not *record* Expression. It just converts CC1 to CC11 on playback. TBH I can't understand why such a relatively straightforward thing should be so hard to achieve considering that REAPER has powerful support for control surfaces and joysticks and whatnot. Has no REAPER user ever thought of this before? It would be great to have a global (or at least per-project) setting that lets you remap midi controller data at the source, before it's routed to a track. Maybe I should post that as an FR. And yes, I'm feeling kinda disappointed here. I love this app and all, but the CC lanes are in a sorry state and now I can't even record Expression live either. I had my hopes up for a while but I'm starting to fear REAPER has a ways to go yet before I can use it full time. :/ But OK. It must be possible to work around this somehow. Is it possible to open up midi items in an external editor, much as you do with audio items?