VirtualFile from full path on disk

I'm working on a plugin where one of the features is to open a referenced file from within another file. I am able to get the filename to open from the current editor, and the path to the parent directory using:

Now, I need to open the file referenced by the combination of the parent directory and the filename (i.e. new File(path, fileName)).

Any pointers for this?

Thanks!

Todd Breiholz