[4E] Create a draw button for power for MTG-like game

Hi,

I'm new at modifying rulesets.

I currently want to DM a game with 4E rule to play a game in the MTG universe.
In order to have something more MTG like, i'd like for my players to draw powers at their turn.

When using the combat mode, a power disappear when the used counter is equal to the maximum (preparation mode).
What i want to do is to use a onButtonPress function (a draw button) in order to set the current value of a power to see it on the combat mode list but for a power at random. For that, the default value of the "state_charpowercounter" (find in the template_power.xml and his script counter_power.lua) should be off to be invisible and the draw button should interact with the state of this counter.

And for that i really need your help.

Thanks for your advice.