How to plot different scales with different ctb onto one roll?

Hi,

I'm having some plotting issues. I have several drawings and which have different scales (1:50, 1:20 and 1:10) all in one dwg file. I made different .ctb files for each of them to make easier to interchange drawings between two different scales. But now I'm plotting each of them onto seperated rolls. I wonder if there is a way to plot all of them onto just one roll?

Thanks.