Point of work-wise (POW) Allocation in rotation

Hi Excel Experts,
I am working Point of work-wise (POW) Allocation in rotation manually,

Now i am looking for some automated task for the same..

- Available data (In a Worksheet) :
We have allocation in terms of D, N, G etc. and OFF,
- Requirement data / Result (in another Worksheet) :
We have to allocate all the staff in following manner in rotation;
21 for D (Day Shift) : D0, D1, D2, D3, D4, D5, D6, D7, D9, D10, D11, D12, DS, DY1, DY2, DP, DR1, DR2, DR3, DR4, DR5.
And
21 for N (Night Shift) : N0, N1, N2, N3, N4, N5, N6, N7, N9, N10, N11, N12, NS, NY1, NY2, NP, NR1, NR2, NR3, NR4, NR5
Criteria
- All D (Day Shift) staff are to allocated in 21 different Point of work(POW) and same for N(Night Shift)
- Suppose, D0 allocated for staff A, in next duty (when he was in D or N; excluding OFF, G, DT etc.), he should be in D1 or N1 and like-wise.. 2, 3, 4, 5, 6, 7, 9, 10, 11, 12, S, Y1, Y2, P, R1, R2, R3, R4, R5.
- Apart from 2 fix allocated persons (DP or NP) all other staffs are to be allocated into 20 POW
- In case of less than 20 let it should be blank in last POW.
(in attached file i have don for 5 Jun, i want the same in all the days(D & N) in automatic manner; Allocation of all the 21 staff in above manner and IN ROTATION to avoid fix allocation;
Kindly help me to solve the above task.
- Ravi