Calculation of Text and Numbers

Hi,

I have a one excel file which have six different sheets and wants total of all sheet in last Total Sheet.
the question is:
1. If the value is all "0" then its wants to show"Nil" value of particular period in Total Sheet.

2. If there is "Not Insured" then in total also wants to show "Not Insured" in Paid Amount column and rest all cells will be blank.

please help.