You can write macro to import file in batch and save (I wrote a SAT batch importer macro long back but don't know where is that now). But with that said, there could be import errors you would have to deal with.
Thought about using the task scheduler, but it only batch imports STEP & IGES.
I will probaby have to wait till i can get access to the workstation it DataKit on it
It is possible to batch convert NX files to SOLIDWORKS with the Datakit plug-in.
To translate an entire directory, you can write a .bat file with something like this:
for /R %%d in (*.prtdtk) do
echo ** Processing %%d **
"C:\Program Files\SolidWorks Corp\SolidWorks\SLDWORKS.exe" "%%d"
You can also do it more easily by selecting multiple files through the Datakit menu.
However, you may need a specific license for the plug-in to enable the possibility to do batch conversion (Maybe you already have it).