That would be doable, you'd have to set up a second set of growth points (so one set for your DS and a more sets for the percentile curves). You can have the percentile curves in, say, light blue and labelled with the level it's at, then have your DS's one in red or something like that. It will take quite a bit of inputting time though.

OR you could find a .jpg of the percentile chart, measure your graph up to it then right-click the grey background and change that to be the percentile chart, I know you can insert your own image to that.