I have many keyboards but main controller is a CLP 170 piano and it doesn't have a modulation wheel. Is there a way to write it in in real time like you do volumes, expression, etc?

Don't know about CLP 170, have 535, but some of pedals have continuous feature to do part soft damping etc.
 
Then you could use a MidiFX plugin to change that controller to a CC#1.
 
There are other midi plugins to replace any CC# to another, a note to CC# etc.
 
Have a look here:
http://www.tencrazy.com/gadgets/mfx/
 
Other things I did over the years was to use a completely other midi unit, a synth, to insert CC# to a track and inserted main notes from another. In this case I had drum pads and I used CC#11 from expression pedal of a synth to regulate hihat openess - in realtime making it CC#04 to make SuperiorDrummer adjust hihat.

lfm
Don't know about CLP 170, have 535, but some of pedals have continuous feature to do part soft damping etc.
 
Then you could use a MidiFX plugin to change that controller to a CC#1.
 
There are other midi plugins to replace any CC# to another, a note to CC# etc.
 
Have a look here:
http://www.tencrazy.com/gadgets/mfx/
 
Other things I did over the years was to use a completely other midi unit, a synth, to insert CC# to a track and inserted main notes from another. In this case I had drum pads and I used CC#11 from expression pedal of a synth to regulate hihat openess - in realtime making it CC#04 to make SuperiorDrummer adjust hihat.

thanks for your time. Yes, simpler to just use one of my other controllers.