I have an existing data base which creates records with a autonumber. I want to have a facility which allows me to attach a additional unique number to a record automaticly, specific records only. Can anyone help!

I can't think of a reason why you might want to perform such a task, please enlighten me.

If you are applying a random unique number for some tagging reason then I'd just add a Yes/No field to each record so you can say whether you want to include it a queries results which you can then employ for some alterior motive

Alternatively, I would consider either using an RND function with a 200,000,000,000 but I've heard the RND isn't assured to be random.

Seems an odd objective mind..

Ian