The REGEDIT syntax is as follows:
REGEDIT [/L:system] [/R:user] filename1
REGEDIT [/L:system] [/R:user] /C filename2
REGEDIT [/L:system] [/R:user] /E filename3 [regpath]
/L:system Specifies the location of the SYSTEM.DAT file.
/R:user Specifies the location of the USER.DAT file.
filename1 Specifies the file(s) to import into the Registry.
/C filename2 Specifies the file to create the Registry from.
/E filename3 Specifies the file to export the Registry to.
regpath Specifies the starting Registry key to export from.
(Defaults to exporting the entire Registry.)