AMB20 USB to Serial lead

[Yadayada]

Hi All, I've had to replace our clubs old laptop used for timing.
We still use an AMB20 system over the serial port.
I'm looking for a USB->Serial lead that will work with the AMB20 and the replacement laptop.
I've tried a couple but neither worked, they both used the "profilic" chip.
Does anyone know of a lead that will work ?

Thanks
Paul,
Frodsham MCC.