I have in my keyboard some fader I'd like to use for volume and dynamics,
how to get to know which midi signals control them?
thanks

If you click on the Options tab on the main User Interface, and then click on MIDI, you will be presented with a list of Midi Continuous Controller numbers, and their corresponding effects upon Pianoteq.  In the case of Volume, you will notice that Pianoteq (as well as a wide majority of other musical plugins and hardware) is hardwired to correlate audio volume with CC#7.

So, if you are able to assign a fader on your keyboard to send Midi Continuous Controller #7 to Pianoteq, then you are in business!

HINT:  If you do decide to permanently assign a specific keyboard controller to send CC#7, you may have to "waken" Pianoteq's response to this controller.  In such a case, you may seem to hear zero volume upon first opening Pianoteq; your countermeasure is to push the keyboard's controller to full-on, then pull back to full-off, and finally to some midrange value -- to align the output of your keyboard to Pianoteq's receiving input of CC#7.

Hope this helps,

Cheers,

Joe