Guitar tablature fret selection problem

[Torquil Macdonald Sørensen]

Hello, I am having no luck trying to get lilypond to specify fret 12 on the 
third string, for the first note in this example:

\new TabStaff { g4\3 f\3 e\3 c\4 }

I could not get it to work using TabStaff.minimumFret

I would like the tablature to look something like the following:

-   -    -    -    -  -  -  - 
-   -    -    -    -  -  -  -
- 12 10   9   -  -  -  -
-   -    -    -   10 -  -  -
-   -    -    -    -  -  -  - 
-   -    -    -    -  -  -  -

Best regards
Torquil Sørensen