Hi Partha,
How are you accessing the Citadel database in LabVIEW? You can use the DSC Module for LabVIEW, and Diadem also interfaces with Citadel. If you are able to read data from the Citadel database, there are example programs that can create and work with XML files under Help >> Find Examples, then Fundamentals >> File Input and Output.
I hope this helps, and if you give more information about how you are using the Citadel database, it would be easier to give you some more help.
Thanks,
Stephen
National Instruments
Applications Engineering