Convert NetworkCredentials to a PSCredential?
$cred = new-object PSCredential($nc.UserName, (ConvertTo-SecureString $nc.Password -AsPlainText -Force))
[System.Reflection.Assembly]::Load("System.Management.Automation")$dc = [System.Net.CredentialCache]::DefaultCredentials$psc = New-Object -TypeName System.Management.Automation.PSCredential -ArgumentList $dc.UserName, $dc.SecurePasswordThat would do it, except that the default credentials are not set for the current application domain in which PowerShell is running.
At least this illustrates how you can create a PSCredential from a persisted username and password. The SecureString is always a bummer but I believe NetworkCredential offers a plaintext constructor you can use and a SecureString property to read from.