You can use something like this:
Code:
  var %c -1
  while ($calc(%c * 900) < $bvar(&binvar,0)) {
    inc %c
   %something_ [ $+ [ %c ] ] = $bvar(&binvar,$calc(%c * 900 + 1),899).text
  }

(sorry if there's any bug in the code, here it's the 02:36AM...i'm very sleepy crazy)