hello and thanks for answers.
ok, i install a veeam proxy on the sbs server and create a network share to a NAS (QNAP/Synology/ ...) as repository to the remote site B&R installation. now i can backup to B&R with permissions on the NAS. the VAW and the proxy recognize it as local and backup over local network. on the remote site B&R i define a new backup copy job (Windows Agent) to an other offsite location to the sbs server and will be happy.
i will try this