I believe you have at least two options:
1) Register Scans
2) Geo-Reference Scans
Option 1) would transform all overlapping scans to one local coordinate system of the reference scan
Option 2) would independently geo-reference each individual scan into you global or local coordinate system providing you know coordinates of at least two points captured by each scan
In TBC to to Support -> Help -> Type "register scans". Possible workflows are described in detail.
