[Tyhm]

@id. Thanks guys, there's no way in hell I would have guessed that one on my own. Seriously. This was my last resort, I went all the way through the wiki (incidentally, there is no mention of Dynamic Variable Call, that would be too easy!). I spent about half an hour trying every variation on clientr.item_#s(id), clientr.item_(id), clientr.item_#v(id)...I think I even did try a couple @s, but I didn't think I was getting any closer.
This is like one a those old text adventures:
"PUSH BUTTON"
"I don't see a Button here"
"PUSH ON BUTTON"
"I don't know how to do that"
"PUSH THE ON BUTTON"
"I don't know how to do that"
"PUSH ON THE BUTTON"
"You push the on button..."