Copying duplicate rows

Hello everyone,

i hope someone can help me out; i put the question in the excelsheet, but here a summary;

With vlookup i gathered some results from other worksheets.
There is a column called "Firm" with a standard value "3000"

Now i need to do the following; for every row i found results (the formula in the upper row will be copied down every time) i need a duplicate of that record with only one modification; the value "3000" has to be replaced in the duplicates with 3005, 3010 and 3010

Please please help me!!! Thank you all in advance!!