Look at Midi Designer Pro, Lemur or Touch OSC…
Different prices, different levels of complexity and capability…
Sure you could get Touch Osc or spend more and get Midi Designer Pro and knock yourself up some faders and mute buttons without any problems if that’s all you see yourself wanting to do
but…if you did go for Lemur though there are so many great templates in the user library that you will likely never need to program anything yourself (unless you have a serious desire to kill some time) …and the one for the octatrack by kraftf, although he says is unfinished will do all you want to do and way, way, way more. And although there’s one page in there that I haven’t quite figured out (probably the unfinished one. lol), it’s pretty easy to set up and work out what everything does.
for me it has been worth the lemur entry price on its own…