Excel formula carrying forward in protected sheet

Hi,

I have an urgent requirement.

I created a couple of forumulas on some cells and hence locked them so that the user cannot enter anything in those cells. I have protected my sheet also with a password.

Now this sheet is to be given to a set of people who will enter the data in the active cells and will be adding more lines as the data increases.

The issue I am facing is that when the user tries to insert a new line, the sheet is promp[ting for a password. I am not giving them the password , but want them to be able to add more rows that carry forward the formula.

Any help on how to do this is highly appreciated,

Thanks,
Srinivas.