Code:
alias reverse {
  var %c = $len($1)
  while ( %c ) {
    if ( $asc($mid($1,%c,1)) != 32 ) {
      var %r = %r $+ $mid($1,%c,1)
    }
    else {
      dec %c
      var %r = %r $mid($1,%c,1)
    }
    dec %c
  }
  return %r
}

Stick that in your remotes and type //echo -a $reverse(text), it should give you "txet".