Start pattern at any point in pattern in Excel

I am busy creating a shift system in Excel. At the moment my shift pattern is DDDNNNOOO/DDNNOO/DNODNODNO (333-222-111111111)where D= Day shift, night shift and O = Off.

I managed to be able to create a spreadsheet that will automatically pick up this pattern and fill it across the whole year, but I would like to be able to start at different starting points in the shift pattern and it should be able to continue with the pattern.

Ex: Shift 1 : Start at the 1st letter in my pattern and continue

Shifft 2: Start at the 3rd letter in my pattern and continue

etc..

Thank you in advance