What you are trying to do is very dangerous!

But, if you have already done it all on one XP, then you should be able to export all your registry changes (into a *.reg file); edit it to remove (with the minus operator)--(* this is the dangerous part) the keys you are changing--(e.g., "[-HK....]" or '"Value-Name"=-' each followed immediately by the NEW Registry HKey or Value-Name); transfer it to the new XP; then merge it into that XP's Windows-Registry. (* The danger is that you might remove too much: something that isn't in your changes, but needs to be there in the new XP.--For this reason, using the Value-Name method is safer than using the Registry HKey method.)