I am not sure of the exact settings for Excel 97. This will also depend on your operating system.
I am also assuming you are printing the report to the txt format and parsing the data in Excel.
There should be an Advanced button on the screen to format the columns you are importing. If you click on this button, there may be a selection to tell Excel the negative is trailing.
The other posible solution is to adjust the numeric format in the regional settings on the operating system. This is under the control panel. You can format the number to a trailing negative there, which should allow Excel to recognize it properly.
Hopefully one of these solutions will work for you.