Data entry in two excel files using a form

Hello,

I have two excell files "a.xls" and "b.xls" both are having Three sheets "Sheet1", "Sheet2" and "Sheet3".
Both the sheets are protected by passwords.
In file a.xls I have created a form for data entry.
I want to keep the b.xls clossed always.
My requirement is to enter the data in "Sheet 1-a.xls" and "Sheet 2-b.xls" using the form in a.xls in the same manner, simultaneously.
Pls, help me....