Keys stored on PKCS11 module and openssh-certificates

[Manon Goo]

Hello,

Does ssh-add offer any possibility to add a  pkcs11-token and a ssh 
certificate from an additional file to the ssh-agent?

I have tried "ssh-add -s ~/lib/opensc-pkcs11.so ~/.ssh/mykey-cert.pub" but 
this does not work, and the code after line 276 ("276:        /* Now try to 
add the certificate flavour too */" )  in ssh-add.c seams assumes that the 
certificate is related to a private-key from a file.

Is there any other way to use ssh-certificates together with pkcs11 tokens?

kind regards,
Manon