I really want to capture the argument uid=13. The uid is the part that will be the query to the db to get the custom data. However that variable gets set I'm okay with.
If we can get $uid=xxx then I can plug that number into the db query and get the custom content.
BREAK....
Okay, so I'm a little slow at this. But the light has finally gone on!
I was trying to capture the uid variable wrong, just as $uid. It needed to be $_GET[uid] !!!
The RewriteMap and RewriteRules are working splendidly.
I've been lost in this forest for so long I forgot what a tree looks like!
Many thanks for your help, and patience with me.