That probably doesn't do quite exactly what you want because with multiple objects selected it moves everything as one big block rather than each object individually. But if it does what you need with one object that should not be difficult to modify for you.
Then for the export, do you export all these objects in just one .obj file or do you want something like a separate file for each one?
Hi Simon,
there is a batch export script that i wrote to export multiple parts to stl format (other formats possible).
Every part you export has to have a unique name.
It doesnt change the origin befor export but this shouldnt be a big thing if you are familar with scripting MOI.