Is it possible to run as a specific user?

We host applications on VMs in Azure, these VMs are load balanced and have shared storage, this is accessible via a folder on a UNC path using access keys, and in our case have setup a user with access to these folders, we have set this up as a mapped drive on a drive letter but connectivity is lost on from the admin user account which means the backup failed on that folder.

Is it possible to run the backup under a specific account?

Thanks

Sorry, but there is no way to do it.