couple of methods:

Code:
  var %x = 1
  while ($$mid($nick,%x,1) !isletter) inc %x
  if ($v1 isupper) {
    ; commands
  }


the extra $ in $$mid() makes it /halt if the nick contains no letters. you could also be sneaky and use if ($v1 < a) which checks it's upper case (lexicographic comparison) :P

or the regex method:

Code:
if ($regex($nick,/^[^a-zA-Z]*[A-Z]/)) {
  ; commands
}


which also checks it's uppercase

"The only excuse for making a useless script is that one admires it intensely" - Oscar Wilde