Regular Expression Help

I’m trying to come up with a Regular Expression that will give me
EX: AS.0123AM02.L

“*” = Any Uppercase or Digit

I can get the following

  • The 2 beginning charaters: (\d|[:upper:]){2}
  • The 4 digits: \d{4}
  • The last character (L|M|R|O|S|Z)

so this:

I just don’t know how to generate
the 4 ALPHA/DIGIT part
It seems anything I put after the (\d{4}) gets “corrupted” - ie, it goes haywire.