I believe Export Part gives you the options you're describing and allows you to choose a specific file to which to export or you can also choose to export to a new file. Import Part will import EVERYTHING into the existing part file (drawings, models, etc.).
Tim Flater
NX Designer
NX 11.0.2.7 MP11 Rev. A
GM TcE v11.2.3.1
GM GPDL v11-A.3.5.1
Win7 Enterprise x64 SP1
Intel Core i7 2.5GHz 16GB RAM
4GB NVIDIA Quadro K3100M