If you work for a contractor and are extending your Terramodel back to the estimating dept., you should consider using Paydirt software. It is made by the same people that make Terramodel and your 3D dozer controls (Trimble). Paydirt is easy to learn and use and has direct import/export to TM as...
You can import files directly into Paydirt if they are "cleaned up" CAD files. In other words they need to be only the layers with contours and the contours must be 3D. The new Paydirt does indeed have Terramodel CAD imbedded so it makes it easier to clean up any CAD files you may have...
There is a new version of Paydirt available for current users. You can download version 5.11 from the Trimble web site. This is the best earthwork take-off program on the market in my opinion. The ease of data entry, types of reports, accuracy, and support place it far above anything else I've seen.