BIOSSET does not seem to be able to modify the CSM setting.
However, DSKFLASH (part of DeskView Client which is also available for download for the LIFEBOOK E7x4) can be used to create an archive (BUP file) of current BIOS settings and then flash these settings to other identical systems with identical BIOS versions.
The DeskView Client package includes manuals in English and German documenting the available command line parameters of DSKFLASH.
I made a quick test and was able to apply the archived CSM setting to another LIFEBOOK E7x4. Unfortunately, the SECURE Boot setting did not transfer.
However, the SECURE Boot can be enabled (but not disabled) using BIOSSET.
But a Supervisor password needs to be set in the BIOS Setup, and you need to include this password with your command line for BIOSSET.
There might also be some hidden command line parameters to enable/disable CSM using BIOSSET.
If you have further questions, please contact your local Fujitsu support: http://support.ts.fujitsu.com/IndexDownload.asp
The Help Desk can open an official ticket and forward it to the corresponding engineering team.