Programable Key

[vuck]

Regards,
I'm trying to configure a programmable key that works in the following way:
Pressing the softkey: dial * 33 and turn on the light button. Pressing the softkey again: dial * 34 and turn off the button light.

Something similar to the function: "forwarding". While forwarding is active the button light stays on, and pressing the softkey again the button light turns off and the forwarding is disabled.

I do not want to use two softkeys, I want the same softkey enable and disable my custom function.
This is possible?
Thank you for your help.
Roberto