Column dimension

Hi

I think you are making some confusion there.
Please looks at this pagewith module positions available on TWN2.

"left_top" and "left_bottom" will always have same width; in other words the left column width value.
What you can do is to have "left1" and "left2" module positions with different width. By adding % value on "left2" the result for "left1" will be the difference.

Cheers