To find what your looking for in the save games folder of Z:SS you'll find files of the 'sz2' variety. NOT the 'sz2.snf' file.
To search with hex look for the code 00401C46 and right beside it will be another 00401C46 and the a few numbers down the row you'll find it again.
This is where the 10,000 credits are for the first scenario game save.
Below is a list of the even credits from 10,000 on up to 15,000: