Online help (as of LabVIEW 7.0?), Index, Command Line, User-defined arguments - It will show you the following:
You also can pass LabVIEW-defined or user-defined arguments when you launch LabVIEW from the command line. To pass user-defined arguments in the command line, enter two hyphens (--) surrounded by spaces before the set of user-defined arguments. LabVIEW does not use any arguments after the two hyphens to launch labview.exe. LabVIEW passes the arguments after the two hyphens to the block diagram of the VI you launch. Use the Application:Command Line Arguments property to read the user-defined command-line arguments passed when LabVIEW launches.
For example, to launch mycool.vi and pass user-defined arguments, use the following command:
c:\labview\la
bview.exe c:\coolapp\mycool.vi -- 1000 sine
On the block diagram of the mycool.vi, use the Application:Command Line Arguments property to read the 1000 and sine arguments you passed and handle the values.
Enjoy,
Roy