We have two drawings, each in its own coordinate system (CS). And both have to be used in a third CS. The two drawings will continue to have work done on them so using map to insert them (and convert) is a lot of work.

The drawings do not contain any Civil 3D stuff - but we are using Civil 3D 2011. They have lots of LDT stuff and plain acad line work.

Is there a way to xref the two files into the third CS and have them translate properly. The drawings are of entire counties so they have to be more accurate than just a straight xref.

Thanks