Barcodes

Hi, I have an alot of barcodes in an excel spreadsheet. I need to inerst two zeros infront of them (eg. 00.....). I've tried to do the first couple but when I have put the zeros there they are automatically deleted. How do you make them stay there and is there anyway that I can insert the zeros infront of all the barcodes without deleting the barcodes themself (eg. formula).

If your barcode is in A1 try this formula in B1

="00"&A1

OK, but I already have a different barcode in B1, the barcodes are set out like this:
Item Code Item Name Barcode
9836 Doll 123123123
3432 Doll Clothes 123123122
And so on....
If I enter the formula then it will delete the second bacode and also I can only have one barcode per item because of how it is imported into a program.