User Placement Rotation Algorithm -

I am trying to come up with an algorithm that provides users "Q", "W", "E" , And "R" for a different line position ("A", "B", "C", "D") after each iteration of a job. I have tried to solve it manually (using different combinations) and can not, so I'm obviously having a conceptual problem (or no ideal solution is possible, my obstacles are given) Any If you have suggestions in the code, do not hesitate to use any language.

Thank you!

I have some obstacles:

• Change the frequency of each user (Q, W, E, R).
• The next "Frequency" column can not be placed in the "D" column in "A".
• The user "e" can not be equal to possible distribution in all columns of "A", "W", and "R" (meaning, for example, the user "Q" In a column, users should not be too much in comparison to "W" and "R".)

    ABCD 1 2 3 4 5 6 7 8 9 10 And after the error, I think it works?   
   
   
    ABCD1QRRE2RQ33QR 4WQ5QVR6Wirk 7RQE8WetQ9RequusQWE (repeats with 1)  
   
   I got the first three rows from rotating the Q, W, and R. 
   
    QWR WRQ RQW  
   
   Then insert those three rows three times below each other, once in the column, the rectangle, column one column and column One of the B 
   
    QWRE WRQE RQWE QWER WREQ RQEW QEWR WERQ REQW  
   
   Then finally manages to rotate those two rows, as long as they have the first two demands Do not meet.