This would be a possible solution, use arrays for pitch yaw and roll, and the variable c_w that indicates what array index you are currently working with.
dim pitch#(2),yaw#(2),roll#(2) ; <<<<<<< add this While Not KeyHit(1) UserControls() If KeyDown( 208 )=True Then pitch#(c_m)=pitch#(c_m)-1 If KeyDown( 200 )=True Then pitch#(c_m)=pitch#(c_m)+1 If KeyDown( 203 )=True Then yaw#(c_m)=yaw#(c_m)-1 If KeyDown( 205 )=True Then yaw#(c_m)=yaw#(c_m)+1 If KeyDown( 45 )=True Then roll#(c_m)=roll#(c_m)-1 If KeyDown( 44 )=True Then roll#(c_m)=roll#(c_m)+1 RotateEntity redcube,pitch#(0),yaw#(0),roll#(0) RotateEntity bluecube,pitch#(1),yaw#(1),roll#(1) RotateEntity yellowcube,pitch#(2),yaw#(2),roll#(2) If KeyDown (19) HideEntity bluecube HideEntity yellowcube ShowEntity redcube c_w=0 EndIf If KeyDown (48) HideEntity redcube HideEntity yellowcube ShowEntity bluecube c_w=1 EndIf If KeyDown (21) HideEntity bluecube HideEntity redcube ShowEntity yellowcube c_w=2 EndIf ...continue with your code