6.03 is nowhere near as old as 5.31. v5.31 is 6 years old out of mIRC's 9 year history whereas 6.03 is only 2 years. It's not the same thing at all.
I'm unaware of any script that works with 5.31 that will lock mIRC, and I am unaware of websites which still support 5.31 scripts. Perhaps, rather than picking at my post and giving me advice on how to help others, you could do it yourself?
- Although, personally, I think the best advice to give to someone using 5.31 is to upgrade (which is what I did).