Hello Antonio,
You will obviously be using a device of 128kB flash capacity, with paged memory. It is likely that you would make use of the linear address pointer (LAP) to access the data. Perhaps AN3730 may help to understand the process.
To directly program the data into flash, perhaps the HEX file should be adjusted for the required address offset, which would then be converted to S-records, that could be manually incorporated into the S19 file for the program.
One complication is that the data would need to be handled as two blocks, because of the position of the interrupt vectors, etc. Your data read code would need to take into account the transition from the lower block to the higher block.
Regards,
Mac