You can export FLM files to 264 videos using Adobe Premiere Pro.
Convert Adobe Premiere filmstrip file to H.264/MPEG-4 AVC video data.
We found 2 software records in the database related to .flm to .264 file format conversion.
Microsoft Windows software - convert flm to 264 on Windows
A timeline-based video editing software from Adobe
Convert from flm file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned flm to 264. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
Apple macOS / Mac OS X software - convert flm to 264 on OS X
Mac version of Adobe's prime video editing software