Do it the "hard" way and enhance your navigation skills. LORAN interpolators are available at boating stores and are cheap. Once you find your spot on a chart with the interpolator, it is a snap to determine Lat/Lon
Here is the link to the free software. I have to warn you that MakoMike is correct. Part of the reason for the conversion not working correctly is that Loran signals have a margin of error of +/- 1/4 mile. That is the main reason why in five or six years the Loran system will be shutoff.
The second reason is that Loran signals work on radio waves that only travel in a straight line and do not take into consideration the curve of the earth. Lat/long coordinates do. The two simply do not convert well on paper or computer.
Here is the link to the free program. It is a DOS program but it runs very well;