Actually the Cm/C tunings can be not only used on Dougie's work but also Joni Mitchell as mentioned and Tom Rush uses it alot.....Tom Rush has a really good instructional DVD breaks down his songs step by step in both C and G tunings. You can find it at TOMRUSH.COM. I'm hoping Mr. MacLean will find the time to do something similar....Not Lie Down is one of my all time favorites. I believe its capo on the 3rd fret in a CM tuning...
Jack