@The guys posting above: Learn to read the request properly. If you cannot post anything new to the thread, you should simply leave it alone. Spamming leads to nobody's opportunity.
@Topic:
I'm using the german world editor and will try to translate the lines into english.
Select that item in the Object Editor.
You need to check the line "usable" and uncheck the line "perishable".
If that does not already work, give your item an ability that can be cast without targets and has no effects. Put that ability to the top of your item's ability list.
The charges of that item may be substracted. If that is the case, you can increase the number of charges on that item using a trigger (Item- set charges remaining to X).