Thank you for so much more.  I really appreciate your in-depth explanation.   Trying just the basic example you gave me returned an error that 2,800,000 combinations would be required and the app exited.
So it appears I need to make this more concise.   

^%A            (starts with uppercase letter)
%2,4d$         (ends with 2 to 4 digits)
%3,7i[0-9a-f]  (3 to 7 characters of 0-9, a-z, A-Z (not at the beginning and not and the end))

Always starts with a uppercase   ^%A
Always ends with 2 to 4 digits     %2,4d$
I never use special characters and the total length is between 8 to 10 characters   
additional info -  After the uppercase first letter then no other uppercase letters,  Other than the last two or four digits no other digits are used. 

In your above example %3,7i[0-9a-f]    % is wild   3,7i[0-9a-f] = anything from the second char through the 7th can be 0123456789 abcdefABCDEF.   But I am having a hard time understanding how to exclude any digits other than the last two or four AND [0-9a-f]  looks like I want only letters a-f.  Dont I want it to be [0-9a-z]?   or is "f" just a symbol that means a-z?


I have this reference
%1,2in- between 1 and 2 characters long of digits, lower or uppercase letters
%[chars] - exactly 1 of the characters between [ and ] (e.g. either a c, h, a, r, or s)
%1,3[chars] - between 1 and 3 of the characters between [ and ]
%[0-9a-f] - exactly 1 of these characters: 0123456789abcdef
%2i[0-9a-f] - exactly 2 of these characters: 0123456789abcdefABCDEF

So If I wanted to exclude all digits (and special) other than the last four  I could write  %3,7i[a-f]?