It can, use something like:
:/multimedia/Shares /opt/shares nfs timeo=20,rsize=2048,wsize=2048,async,rw,nosuid
There one thing to remember though: After you have mounted the share you should not forget to set the rights on it so that your aMule user can actually write to it and that non-group users can not read the files:
chown -R amule:users /opt/shares/*
chmod -R o-r /opt/shares/*
This is for an NFS mount, I don't know if the samba mounts automatically inherit the rights of the mount point.