CUP BOOST FOR UK & IRISH RAIDERS Australian officials today announced that winners of this year`s Doncaster Cup and Irish St Leger will be guaranteed a run in the Tooheys Melbourne Cup. They will be exempt from the ballot for the big race, which has a safety limit of 24 and is invariably oversubscribed. The race committee also has the right 'in its absolute discretion' to exempt any horse or horses from the ballot. There has been controversy over eligibilty for Australian races in the past. Locals were upset in 1998 when the rules were apparently bent to allow British raiders Yorkshire and Taufan`s Melody places in the Melbourne Cup and Caulfield Cup respectively.