Backup to network share outside the domain

Hi @ all!

I just installed BackupExec 2012 Small Business Edition on a Small Business Server 2008. Running Hyper-V with the to VMs SBS Server and Standard Server with MS SQL Server. BE ist running on the virtaul machine with the SBS.

Now I want to backup to a local harddisc in my comuter. I created a share on the Hyper-V machine. And the Hyper-V machine is not part of the domain.

I can write to the share using logon information from the Hyper-V Administrator account created to the share.

But now BE says, that the BE Service must have write permissons on the share for the BE Service account.

How can I give permission for a domain-service-account to a network share outside the domain??

Greetings

Michael