Passing selected unit to an event?

[GrumpyMel]

Hey guys. Trying to use some of the new functionality in the ATG editor. One thing that seems to be escaping me is how to pass a unit that you select with an action card to an event.

I know ATG lets you select a unit with an action card and the settings on the card to allow that seem pretty intuitive but I can't seem to find anything on where it stores the unit number you selected so that you can pass it to the event the card executes. Can anyone help me out here?

[Lunaticus_matrixforum]

If you select a hex the values are handed to the event on tempvar2(x), tempvar(y).
If you select a unit then the value of the unit is handed to the event in tempvar5.