You can purchase those with an integral BT30 holder. P/N 80.365.30.FHN. About $540.00 depending on where you are.
But if you don't want to spend the money I am pretty sure you can take the shank out of the Haimer, grind it down to .500, mount it in one of these short ER20 Rego-Fix holders. (there may be others available) Or if you have a super-short toolholder or can cut one short, you can always grind-down and silver-solder the shank into the holder and the re-mount it to the taster with the set screws.
But if you don't want to spend the money I am pretty sure you can take the shank out of the Haimer, grind it down to .500, mount it in one of these short ER20 Rego-Fix holders. (there may be others available) Or if you have a super-short toolholder or can cut one short, you can always grind-down and silver-solder the shank into the holder and the re-mount it to the taster with the set screws.