Script changing col's width, whether via the width attribute on the col element, or setting width:500px via css, should work.

col 1 row 1	col 2 row 1	col 3 row 1
col 1 row 2	col 2 row 2	col 3 row 3

col 1 row 1	col 2 row 1	col 3 row 1
col 1 row 2	col 2 row 2	col 3 row 3