I'm not familiar with the I2C interface but you could talk to this instrument through the parallel port.
Here's a link for an example program, "Using VISA to Access the Parallel Port in LabVIEW" http://ae.natinst.com/devzone/explprog.nsf/41ee12ddba6c766a8625684700691463/26c3ef8e7da5feb286256aa0006bd127?OpenDocument
Also I found a couple of other knowledge bases (KB) that talk about your question. If you go to ni.com >> Support >> Advanced Search (option 3) >> type "labview parallel port visa" in the box all words, you will get them.