There are a few ways to import and export files from the toolset.
There are a number of files that make up a module - as documented here on the wiki. Everything is packaged up in the ".mod" file but when opened the toolset will in fact extract everything to /temp0 by default.
The files are then blueprints, areas (and area contents), scripts, compiled scripts and so forth.
ERF Import and Export
The default - and safest - way to export a file to move it to another module is with the "Export" option in the toolset. This allows you to select some aspect of the module and export it plus associated items. This means attached scripts get found and added to the generated ERF file, items equipped by a monster get exported as well and so forth.
Importing it will mean those items get added to the current module. Only problem to note here is if importing things with invalid categories (if you've customised the palette) - a full build may sort these out, if not GFF edits to change the category would be needed.
Direct File Copying
You can also copy files from module to module. This will just copy those exact files. An example workflow to copy a creature blueprint (UTC) would be:
- Open module 1, navigate to temp0 or module folder
- Find <RESREF OF YOUR CREATURE>.utc
- Copy it to a another location
- Open module 2, navigate to temp0 or module folder
- Copy said .utc into temp0 or module folder
- Build and save the module
The caveats here are obvious; the creature may have custom items and need those copying over as well (the toolset will automatically blank those slots if the UTC file is opened when the items are not present so it's still "safe"). The scripts attached to the creature are not brought over if customised as well.