Charley
All you can do in Phocus is convert your 3FR files to DNG, but there will be no edits saved, as Phocus does not use the sidecar xmp files which LR uses, or write any changes to the DNG. If you want to make any changes to an image in Phocus, or use the lens corrections, you will have to export as a TIFF. In which case you might as well go straight from there to PS, and miss out on LR altogether.
John