If your Clarion 4GL code environment has the ability to turn the code into a dynamically linked library (dll) then it is possible that LabVIEW could call it, although it is not officially supported.
Another option would be to use ActiveX. Does the environment have the ablility to add an ActiveX interface to the application?
It looks like we need to know a little more about Clarion 4GL and what its capabilties are. Do you have access to this information? Can you talk to the developers of the code?
Robert Mortensen
Software Engineer
National Instruments