How to back up themes?

Hi,

I would like back up my themes in theme store, but how?
I'm using at the moment titanium back up.

A little explainagen

I have paid themes that are not available in my country.
So when i restore my back up from theme store and themes I'm getting my trials back. So i need to do tunnelbear thing over and over again. I search a possibility to back up fully my themes in theme store without losing full version of the themes.
How can I do this?

Hope someone can help me out.

Sorry for bad english.

Thanks

Aaronito

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