I think probably you can not send both midi and audio to any single channel strip in VePro. You have to choose either an audio input pair, or an instrument plugin(which will produce audio). When you choose an instrument than you have the opportunity to specify which midi channel to use for it, but lose the opportunity to select and route any audio.
I would suggest the work around is to learn how to actually create your own custom parameters in Reaktor, so that you can basically use parameter automation to control whatever it is you want to control inside Reaktor, then you can use parameter automation instead of midi.
If Reaktor can't support that...(I'm not sure, I think it probably does support it, but just in case it can't), then you could look into something like KushView element, put that in VePro and Reaktor inside that. Then in Kushview you can create user parameters I believe, which can be mapped to midi. For sure BlueCatAudio patchworks can do that, but Patchworks has gui problems inside VePro.