The software you describe is used for reporting. FLIR has a software that is called IMAGE BUILDER that will stitch together radiometric images. This SW is designed for the purpose of pasting or combining several radiometric images into one. Get your hands on this software and you will accomplish what you are seeking.
here you can see more 'stitched' images i already did. some of them are fully radiometric, which means you can 'save as' and modify with you infrared software..