Fill cells based on the other 3 cells unique combination the value on the target cell

[dp111]

Hello,


I have the following requirement:

if cells A3, B3, C3, have unique combination, then enter in cell D3, the next 'incremental' value from D1, D2.

Ie: if the the combination of the three cells is unique and for example in D2 is AB002 enter in D3, AB003; if the combination is not unique enter the same as last one.

Thanks a lot,

Dan