The only way I found is to streamline the series as it arrives. So, if I have series A, B and C, and I want it to be ordered using B, C, A, then I add the series in B, C, Aorder so that series [0] = B, series [1] = C and series [2] = A. This is definitely kludge because it would be nice to just sign the stack index instead of resorting to the series import order.