Sshfs virtualbox Linux host win7 guest

I got sshfs working to access linux host user folders from win 7.

However, I can seemingly only mount linux useraccounts from the linux host on windows guest. That works, but there is no way I can mount any other folders on a server even if they are freely accessible by the user accounts e.g. nfs folders etc with standard nogroup and nouser ownership.

I read the extensive and great nixcraft tutorial on sshfs, but it unfortunately do not address the virtualbox with windows or general virtualmachine guest as an option.

Any pointers how I can use sshfs to access nfs folders on the linux host.
\sshfs\ (configured in windows map drive)
is not successful, but useraccounts are.

Is there maybe something on the linux server side I need to do to forward access to the windows client in the virtualbox ?
Cant solve it it seems so I ask.