Hi Kolzau,

Maybe you can double recoding. Let's say you want to order your categories 
in C->D->A->B. First, you can map {A, B, C, D} to {3, 4, 1, 2}, 
then, you can map {1, 2, 3, 4} to {C, D, A, B}. 
To do so, you can do the following: (assume your original data 
is in A(X) and B(Y))

1) For the first mapping, add an extra column C(Y), and recode your 
  categories in B(Y) by e.g., nesting conditional operators in 
  Set Column Values tool: e.g., 
  col(B)$=="A"?3:col(B)$=="B"?4:col(B)$=="C"?1:col(B)$=="D"?2:99
2) For the second mapping, add extra column D(Y), and put the categories 
   there in the order you want in this case {C, D, A, B}. 
3) Make a plot of C(Y) against A(X).
4) In Y Axis dialog box, choose "Tick Labels" tab, and set the 
   Type to "Text from Dataset", and Dataset to the column D.



Hope this works.

--Hideo Fujii
  OriginLab