Hi nitu,
I recommend that you check out the example that comes with LabVIEW. If you do a search in the example finder for bluetooth, one of the results is "Simple Bluetooth Client". This example is doing very close to what you are trying to do (basically, they use a Type Cast function to convert the string returned from bluetooth read to a numeric).
That should get you started!
Best regards,
-Sam F, DAQ Marketing Manager