Triggering a keypad HOLD button function from a car visor VCTX

Hello:

I somehow doubt that this is possible, as I don't think the car visor Tx translates cleanly to the Lutron System, but here is my situation:

I want(ed) to be able to press and hold a button on the Lutron car visor transmitter to open a different garage door. i.e. tap the car visor button to (conditionally) open door 1, but "hold" the button (2 seconds) to (conditionally) open door 2.

I programmed a VCRX keypad button with this functionality and then mapped the car visor tx to this button, but the hold function does not work from the VCTX.

Any ideas on a workaround? I don't need to hear about the multi-button workaround - I know that the car visor has 3 buttons, yet 7 functions. I figure i will have to use this, but I'm actually using all 6 of the VCRX keypad buttons already, and so I don't really want to give up a different button to be able to open door 2.

The VCTX will only be able to send a button press. It cannot send a double tap or a hold to the VCRX keypad.