A converter exists to save Google Sketchup files to .obj files for free on the Internet. Search for it (I don't remember the link) and use it, then download
Blender and import the file. Use Blender to add the relevant nodes, mount points, etc. and fix up the model if you need to, then use Blender's
DTS Exporter. Blockland accepts DTS models for things in-game. You'll need to edit or write a script for it and package it correctly.
