Agree with Martin.System generate some assignment number which reads every column needs to be displayed in the report.
That's how the virtual KF concept comes into the picture.
I have used the ABAP code to update the reporting column before displaying the report output.
Using some select statement and assigning updated values by reading some data extracted from ECC.
Please search for virtual KF and CHAR docuemnt's if you thinks your requirement can be fulfilled by it,.
Thank-You.
Regards,
VB