Cost of Goods Macro for New Period

Hello,

I have finished formatting a new COGS sheet and when any given period is up I would like to create a Macro to refresh the page to 0 values for all lighter colored areas of the sheet. However, I need the last recorded $$ inventory of each section to assume the beginning $$ inventory number of each section - whereas a new period may begin with the beginning inventory number in place. The other stipulation is that sometimes there are 4 week periods and sometimes 5 week periods - so the last inventory cell # could change. Do I need to create 2 Macros for this ? A 4 week and a 5 week?

Also, I would like to protect the sheet in certain areas (specifically any of the darker colored areas). The lighter areas are for data entry only.

For cell # reference :

In a 4 week reset G5 would become D3 for Meat
In a 5 week reset H5 would become D3 for Meat

And so on for each section of the Inventory

Adam