I would ask the folks at Mindsensor. How does their documentation say to use it. I'm assuming one of two possibilities
1) If they gave you a custom NXT block, then the block was written using the NXT toolkit so you should be able to extract the underlying block implementation. They can tell you which VI is the one to drag onto your LabVIEW diagram. I see from their website that some of their distance sensors come with an NXT block
(http://www.mindsensors.com/index.php?module=pagemaster&PAGE_user_op=view_page&PAGE_id=73) You should just email them and ask which VI to use.
2) If there was no custom block supplied, then likely the instructions say to use some standard NXT sensor block (like the light sensor). If that is the case, then use the corresponding NXT toolkit block.
Joel Sumner
NI-Shanghai