Yes, copying the multisamples and programs from the old machine is a way to get the library back.
The multisamples by default will be in "C:\Program Files\Cakewalk\Dimension Pro\Multisamples\Digital Sound Factory Symphonic Strings HD".
The programs are in "C:\ProgramData\Cakewalk\Dimension Pro\Programs\Digital Sound Factory Symphonic Strings HD". The ProgramData directory is hidden.
After copying the files make sure to press the F5 key in the DimPro program browser to rebuild the program list.