Hello blackbord, how are you? You can use the doevent command on the first {} found in the item script. Something like this:
670,Gold_Coin_Moneybag,Bag of Gold Coins,2,100000,,400,,,,,0xFFFFFFFF,7,2,,,,,,{ doevent "vip_for_1week::OnPCLoginEvent"; },{},{}
I also have changed the item type from 0 to 2 (Healing -> Usable). Another solution is to change this script to be a function, so you'll be able to use whenever you needed it. I hope it works, good luck.