Control Filter Resonance when key released

[pfrancq]

Hi,
I want to modify the filter resonance once a key is released. To be more precise, by default the resonance is null. When the key is released, I want to resonance to go to a given value and return to zero while the sound is fading out (I have a long volume release). Actually, I control it manually with the mod wheel. But I wonder if this could be automized using a programmable shaping source for the modulation bus. I made a few tests, but didn't find a way to do it. Has anyone an idea if something like that is possible.
Thanks.

[till]

I am afraid there is no onboard modulation source giving you a rising and falling control voltage just in the release stage.