Thorsten:
If your card is PXI or PCI, then you are in luck because NI-VISA will help you. Otherwise, you cannot show your instrument in MAX.
To use NI-VISA for PXI, just get your register description manual from the vendor and follow the instructions in this paper on our site:
http://zone.ni.com/devzone/conceptd.nsf/webmain/ADF3152837E2B4A486256B5600642AC7?opendocument
Good luck,
Dan Mondrik
Senior Software Engineer, NI-VISA
National Instruments