Hehe, this was a bit tricky ;-)
What you need here is a reverse ratio tori.
If you use your outer radius of 10 and you now your inner radius is at 2.5, than it is a space of 7.5 LDU between.
Now you have to substract 7.5 from 2.5 . You will get -5 as an "imaginary real inner radius".
So you have to type 10 for the outer radius and -5 for the inner one in my excel sheet.
You will get Major: 2,5 and Minor: 7.5 -> Multiply by 2 you get 5 and 15. Just put these values in PrimGen2 and you will receive: r04o3000.dat
Fill the your rotation matrix with the major radius to stretch it the right way
Please note, that you have to find a value for the high by yourself. (I did by try and error - but I will think about a calculation solution in the evening) 3.5 for y seems to work. I don't know for the moment. Just try it!
Stupid me - found a solution... Just calculate your high (in your example: 10.515 LDU and devide it by the ratio in this case) - you will get 3.505
/Max
What you need here is a reverse ratio tori.
If you use your outer radius of 10 and you now your inner radius is at 2.5, than it is a space of 7.5 LDU between.
Now you have to substract 7.5 from 2.5 . You will get -5 as an "imaginary real inner radius".
So you have to type 10 for the outer radius and -5 for the inner one in my excel sheet.
You will get Major: 2,5 and Minor: 7.5 -> Multiply by 2 you get 5 and 15. Just put these values in PrimGen2 and you will receive: r04o3000.dat
Fill the your rotation matrix with the major radius to stretch it the right way
Code:
1 0 -12.1 -8.562 0 2.5 0 0 0 -2.5 0 0 0 2.5 r04o3000.dat
Stupid me - found a solution... Just calculate your high (in your example: 10.515 LDU and devide it by the ratio in this case) - you will get 3.505
/Max