Hi Madjid,
I'm afraid that there is no CVI instrument driver available for a Fluke RCL PM6306. There is only a LabVIEW driver available for a PM 6304, what would be a good start. If you have LabVIEW you could use that driver to create a suitable one for the PM 6306 and implement the instrument driver in CVI. There are a lot of examples on our website on how to implement LabVIEW code into CVI.
You can also request NI to write a CVI driver:
http://zone.ni.com/idnet97.nsf/instrumentdriverrequest
Regards.
Joris Vanderschrick
Team Leader Application Engineering
NIBE