Chuck,
I would suggest building the FORTRAN code in your favorite Fortran compiler into a DLL as well as the breadboard code. You can then use the Call Library Function node to call the compiled code. This would be the easiest and fastest method. You could also compile these pieces of code and link them to some C/C++ code that you can write and then call this code from LabVIEW. Maybe you can use converter fortran-->c. It is in UNIX.
Here is another post
parameter types in FORTRAN DLL's that has discussion on this topic and a link to the page with explanation of calling parameters. The link is not live any
more, so you can contact the customer who posted the response directly.
Sorry, there are no examples I could find.
Zvezdana S.