Alternate method if you don't want to mess with game prefs:

Make a new sandbox game, pick a big map with lots of space

(optional: turn on cheats, set speed to +4 or variable. Just use cheats to get lots of mass and energy, don't use cheats to place buildings)

Build all of your templates

End the match

On the new computer:

Play the replay file

Step in to your own point of view

Select each of the things you built and choose "make template"

End the replay

You will have the templates saved, they will be there the next time you start playing

This is also an easy way to share templates between different players