Sorry, if I'm not understanding what you're saying. However, yes you can move the .7z onto your card and extract (from what I believe... although I haven't tested this).
What's exactly the problem? You don't have enough space?
The thing is, when you right click a folder it always gives you 2 sizes. On my computer these sizes are 60 and 77 mb.
When I copy the whole folder to my flashcard the sizes changed. There they are 60 and 105 mb or something. That's way bigger than 77, forcing me to remove an extra game. Is there a way to turn the 105 back into 77.
That was basically my question, now explained a little clearer (last time i posted it with dsorganise, so I couldn't typ a lot, that takes ages)