Any way to assign usernames?

[techshare33]

I'm trying a rig a way for my VB forum to require First and Last name. I then want to use that data as the username (e.g. for John Doe the username would be jdoe). It would be nice to have this happen automatically, but since I approve each user I could assign this myself. The problem is the "username" field is required at registration. TIA for any ideas on how I could solve this problem.