Here's a regular expression editor. It's aimed towards Ruby but will do for .NET as well:
I don't know about the detailed specification of the license numbers you#re looking for, but I created a regex based on your example: ^[A-Z]\d{2}-\d{2}-\d{6}$
.
You can modify it here:
The example explained:
^[A-Z]\d{2}-\d{2}-\d{6}$
^
= start of line
[A-Z]
= a single upper case letter
\d{2}
= any number with 2 digits
\d{6}
= any number with 6 digits
$
= end of line
If you want to make sure you don't miss lower case letters starting the license use [A-Za-z]
instead of [A-Z]
(Thanks to Paul Sullivan)