Lock certain cells in a row, depending on another cell in the same row, & apply to sheet

Hello!

I have a spreadsheet that has a cell (L) that indicates how many individual items were used for that row.
Cell (L) can equal #N/A, or 1 through 6.

If if (L) = #N/A, then I would like to lock (M) through (AE).
If if (L) = 1, then I would like to lock (P) through (AE).
If if (L) = 2, then I would like to lock (S) through (AE).
If if (L) = 3, then I would like to lock (V) through (AE).
If if (L) = 4, then I would like to lock (Y) through (AE).
If if (L) = 5, then I would like to lock (AB) through (AE).
If if (L) = 6, there is no need for any cells to be locked.

I know how to enter information into VB, but I don't know how to make it run automatically in a workbook / spreadsheet.

Thanks for looking at my problem.

Cheers,
Rosemary

Hi. I have a dynamic dropdown in a sheet. (file attached)

B4 is drop down for Months and cells below it are dropdown for the days of the selected month.
My gripe is I cannot lock the dropdown cells for days (in this case 4-Jan-16) and user can still edit it.

I tried to protect the sheet and checked Select locked cells, select unlocked cells, use auto filter. User cant input data aside from the choices on that drop down cell, but cannot also picked from the choices.

What I want is for users not to input anything on that cell and only choose from the drop down options.

Please help.
Thanks.

PS - cant insert excel file. rename it as jpg. pls rename it after downloading. ThanksPRODUCTION TRACKER 2016.jpg.xlsx