One-time-only item acquiring?

[Nimono]

Okay, I was wondering....

Say I made a script that were to create an item if you used the Wand on a certain combo, but if you left the screen, came back, and did it again, the item would not appear. How would I go about doing this? I can't use checks, because then the check would carry over to all other screens (I'd have to make it global), and if I had another screen you could do that on, I'd have to do a screen-and-map check, like I did for my Cane of Somaria script, but.... That would make it so if you came back to the first screen after getting this certain item from it, you could get it again if you went to another screen like it. I'm not sure what to do.

[C-Dawg]

Global variable, or tie it to secrets on the screen.

[Nimono]

Hmmm.... Well, I don't want to do a Global Variable, because then, everyone would have to use different combos and variables for each of their buried items... How would I check for a Secret Flag, then? Oh yeah, and on that subject, how do I permanently change a combo/flag for a screen? You know, so it won't reset ever?