Hey @spalle
Try this:
1. In the Aux Envelope section turn the Destination Knob to "OscAll Freq"
2. For the Aux Envelope Amount, turn up to +48 (you can adjust this to taste... +48 would be two octaves rise in the attack stage)
3. Set the Attack, Decay, Sustain, Release. From what you've said, I'd recommend starting with 115 attack, 0 decay, 127 sustain, 100 release. The sustain at maximum will make it so after the attack stage is finished, it will hold at the top frequency. You can adjust the ADR timings to taste, depending on your sound design needs.