Wow, my first question was answered by the frontend creator! Thanks!
Well, not sure if it is correct, but I wrote the following code:
iFreq = p4 * semitone(chnget("Pitch"))
iAmp = p5
iAtt = 0.39
iDec = 0.0
iSus = 1
iRel = 0.53
iShape = 10 ; Square wave
kEnv madsr iAtt, iDec, iSus, iRel
aOut vco2 iAmp, iFreq, iShape
outs aOut*kEnv, aOut*kEnv
It seems to do the trick when I change the "Pitch" Knob. I don´t aimmed midi mapping yet (it´s the first time I code Csound/Cabbage, newbie, still learning...). Should I consider another important question?