Maintaining Vouchers in Excel

Hello Guys,

I have to maintain a payment voucher's excel file for maintanence, washing, etc. The problem is, currently this task is manual. I would like it to be simple and less time consuming.
Now, let me explain what my voucher file consists of:
1) Each sheet belongs to one invoice, against which a payment voucher is made.
2) Each sheet will contain the same format of the payment voucher, but the details will change. (for example: name, registration no. and so on)
3) Multiple entries for one employee is recorded in different worksheet within the same file.
4) This is a file which is maintained monthly. (One file for one month)
5) We have a fleet of over 300 vehicles, so the data will b large.

I know its too much to ask, but you guys can really make life simpler and so i make asking you guys a favor.
So could someone please help me with a simple way of maintaining this sheet. I would like the following things to be in the excel sheet:
1) As i click on the new sheet tab below, the format of the payment voucher should automatically come to the next sheet, and so on.
2) Each payment voucher should contain a unique voucher number. For example, Sheet1 has Voucher # 0001, Sheet2 has Voucher #0002. This also should be updated automatically as i click on the new sheet. This should appear on the top-left of each sheet
3) All the page setup should be exactly same (The printing range, margins, etc.)
4) There will be a field where the car registration number will be entered. Is it possible to rename the same as the sheet name below. If multiple entries, then it should come as the following, 15678, 15678-A, 15678-B, etc.
5) A summary sheet in the beginning of the worksheet, which displays Serial No., Car Registration Numbers, Name & Voucher Amount same as the details entered in the sheets.

I have attached our current shitty & shabby format just for our reference.