Please see below on the best approach
You basically had the right idea on solving your issue.
You just have to pass 1 variable to the function, an Array with the controls.
Code:
// pass one variable to the function : an Array with the controls you want to adress
disableKey(["key1", "key2", "key3"])
function disableKey(target:Array){
for(var i=0; i<target.length - 1; i++){ // Array is 0 based, so loop the length minus 1
doSomeThins(target[0] as DisplayObject);
}
}
private function doSomeThins(control:DisplayObject):void{
trace('do something with control : ' + control);
}