I have a Comodo email certificate installed in Firefox 20, and I've tried (and failed) many times to export the certificate as PKCS12 (error is "Failed to create the PKCS #12 backup file for unknown reasons.").
Since Firefox can't do this job, is there an external tool to do this? Possibly on the command line? I'm on Linux, OpenSUSE 12.3 x64 with KDE 4.10.2.