So, it looks like I would need to know what the (pixel) width of a single digit would be in the standard font -- if I knew that, it's fairly easy to compute the sum of the column widths and from that to determine whether the columns would fit if printed in portrait. However, I don't know how to determine what that (pixel) width would be.

For now, I guess, I'll just assume that my standard font matches my users'. (Not the worst assumption ever, but certainly not optimal).

Thanks,
Jim