Mine

alias blah {
  //var %x 1, %dir "c:\pasta fica\aqui\", %er = /^DS9(\d\d)(\.jpg)$/ 
  clear 
  while ($findfile(%dir, *.jpg, %x)) {
    var %c = $v1 
    if ($regex($nopath(%c),%er)) 
      rename $+(",%c,") $+(", $remove(%dir,"), \, $regsubex($nopath(%c), %er, Fotos do dia \1 $+ .jpg), ") 
    else
      break
  }
}