Hi Luca,

My first suggestion would be to contact the manufacturer and ask them if they can provide the information you need. Even if it's not on their website, Zemax provides a well-known software package, so it should not be hard for them to create what you seek.

Beyond that, we do have some options at Zemax that might help you. Most are in Knowledgebase articles. A good starting one might be 'Light sources used in illumination design', at https://my.zemax.com/en-US/Knowledge-Base/kb-article/?ka=KA-01825 , particularly the sections on importing and on making objects internally. It also has links to the next two articles I wanted to point out. 'How to model LEDs and other complex sources' at https://my.zemax.com/en-US/Knowledge-Base/article/KA-01590 and 'How to use Osram LED data with OpticStudio at https://my.zemax.com/en-US/Knowledge-Base/kb-article/?ka=KA-01356 . 

Of course if anyone out in the larger Zemax community has converters they'd like to share, please do feel free.