Look on Tools->Preferences->File formats->Format to get an idea which parameters should be passed.
Note that the order of \-e and \-x switches matters.
.TP
+\fB \-E [\-\-export\-to]\fP \fIfmt \fIfilename
+where fmt is the export format of choice (see \-\-export),
+and filename is the destination filename.
+.TP
\fB \-i [\-\-import]\fP \fIfmt file.xxx
where fmt is the import format of choice and file.xxx is the file to be imported.
.TP