implementing a toggle function in x10

[bcboy@xxxxxxxxxxxxxxxxxx]

I'm pretty sure this isn't possible, but just in case, is there any way
(short of dedicating a PC or other high-end device) to implement a
"toggle" function with one x10 code, so a single button will do on and
off (sorta like a garage door opener).

The problem I'm trying to solve is implementing lights on/off commands
from a Homelink unit in a car. It will learn one x10 code on a single
button. I would like to use the same button to alternate between "on"
and "off", i.e. one press should issue the off command, and the next
press (after release) should send the on command. I have a cm11a,
however it appears to be stateless, so it won't solve this problem as
far as I can tell.

I haven't been able to find much detail on the Homelink, but I suspect
the buttons are only capable of sending a single code.

Obviously if I dedicated a PC I could store a state and write a "macro"
that alternates, but that's not really an option for me.