Hi,
FCCU_NCFS_CFG2,FCCU_NCFS_CFG3,FCCU_NCFS_CFG4 as show below are not defined in the basic software.
You just posted the definition of union based in your screenshot.
I do not see where is the issue.
Simply use :
FCCU.NCFS_CFG[1].R = 0x01000; // Short reset reaction
as you can see from header file:

regards,
Peter