I generally make my plugins so that behaviour is possible, but it seems as it's one of my earliest plugins, I didn't take that approach.
That doesn't meant it cannot be done, but instead of using the plugin commands, you have to go to the function.
I'll update this now I know, but for the time being, you have to use the script calls instead.
Let's say you want to copy the entire actor you set on variable 3 into the actor you set in variable 7:
$gameActors($gameVariables.value(7)).copyActor($gameVariables.value(3));
You can replace $gameVariables.value(x) for literal numbers if you want to use the literal id instead of the variable.
[Edit]
Alright, updated it, now you can use any string with a number as "use a variable instead", like for example, variable10, or 10v will both go and check whatever editor variable contains and use it!