Ms excel find unique records 2 sheets & copy to another sheet

I am not expert in excel, Hence I need help to compare Excel 2 sheets & copy the unique records (Selected columns from sheet1 & sheet2) to sheet 3. I give below the following details for your valuable suggestions:

Sheet1(Master) : (Total records more than 10000 Nos)
Column A: Cust_Id, Column B: Cust_Name, Column C: Cust_Place, Column D: Credit Limit

Sheet2(Details): (Total records below 4000 nos)
Column A: Cust_id, Column B: Cust_Name, Column C: Cust_Place, Column D: Sales, Column E: Month

I need to help compare sheet2 with Sheet1 and copy the unique customer details to sheet3.
Sheet3(Compare) (Details required)
Column A: Cust_id, Column B: Cust_Name, Column C: Cust_Place, Column D: Sales, Column E: Month, Column F: Credit Limit (from sheet1)

Sheet 4(Missing records) (Details required)
Column A: Cust_id, Column B: Cust_Name, Column C: Cust_Place, Column D: Sales, Column E: Month, Column F: Credit Limit (from sheet1)

Please help me & inform vb script . If possible please send a sample file to tpra001@yahoo.co.in
Thanks in advance
CSG

In Invoice Sheet – ‘Date’ = sheet order ‘Date’
In Invoice Sheet – ‘Bill No’. = Order Sheet ‘Order’
I need the Products, Rate, Quantity, Value details from Order sheet in invoice sheet.

Regards

CSGanesh