I found a registry setting for v11 but the string value is over 10,000 characters long and regedit doesn't seem to let me paste it into a new string value data field in the jriver/media center 12/properties hkcu key.
So, I recreated one of my column presets in v12 and that at leasted popluated the v12 registry key. Then I was able to paste the v11 string value data into v12 key and it took it. Now all my presets are in v12.
However, all the various playists using the different presets in v11 are still the basic default column layout in v12. I suspect it's tied to the library backup I used to migrate my library from 11 to 12. As a matter of fact I just imported my v11 library backup into v11 on my other computer and the different column layouts are correct for all the playlists. The restore library of v11 to v12 does not carry over these column layouts.