Pakko,
Are you using VB.Net or VB 6.0? If you are using 6.0, things are a little more difficult because the language does not support the cdecl calling convention. You would have to generate a C wrapper that exported the functions using the stdcall convention. More information can be found in this thread:
http://forums.ni.com/ni/board/message?board.id=230&message.id=2257&requireLogin=False
Additionally, it appears that someone has already done this here:
http://forums.ni.com/ni/board/message?board.id=beta4&message.id=2
If you are using .Net, you just have to declare the DAQmx Base functions at the top of your program. Be sure to set the calling conventionto cdecl. More information can be found here:
http://forums.ni.com/ni/board/message?board.id=232&message.id=1524&requireLogin=False
I hope this information helps. Please let me know if you require further assistance.
Regards,
Ryan Verret
Applications Engineering
National Instruments
http://www.ni.com/support
Ryan Verret
Product Marketing Engineer
Signal Generators
National Instruments