Well DBP has a function for saving Mesh / Objects., but it only supports the proprietary DBO Format.
It's honestly that not complex a format...
Essentially it's just the Object Memblock Format., just with some extra components for things like Animation, Audio, Textures, etc.
When it was developed it was a double-edged sword... as from a Loading perspective it was much quicker than other formats, basically because it could just be shadowed directly to memory with an associated ID and the Engine was "Good to Go" as it were; rather than converting to how DBP used things.
Still the lack of complete documentation on it, meant that supporting it as an I/O Plug-In for your favourite Modelling Application was somewhat of a nightmare.
This said, there is nothing stopping you from creating a Custom Importer / Exporter Function; provided you understand the Format that you're Exporting From or To.
There is for example Wavefront OBJ Importer Function Code samples for both DBP and AppGameKit that I've written, just to showcase how simple it is to write such functions....
With this said... perhaps a more important question would be "WHY, do you need such?"
Remember that the FPS Creator and GameGuru (both of which are the only products with Media Packs in DBO Format) restrict the usage of said Media to those Products... so while TGC haven't historically stopped people from doing it, keep in mind converting them and using them elsewhere would be a violation of the License Agreement.