title: Convert Win Form Text input to a variable being used in PowerShell
body: <p>I have built a WinForms GUI to make PowerShell easier.</p>
  
  <pre><code>function CalendarShare {
      Add-MailboxFolderPermission -Identity $FromUser:\calendar -User $ToUser -AccessRights FolderOwner
  }
  </code></pre>
  
  <p><code>$FromUser</code> is a WinForms text input, which needs to work within the function to share the calendar. </p>
  
  <pre>
  Cannot process argument transformation on parameter 'User'. Cannot convert the
  "System.Windows.Forms.TextBox, Text: *@*.co.uk" value of type
  "Deserialized.System.Windows.Forms.TextBox" to type
  "Microsoft.Exchange.Management.StoreTasks.MailboxFolderUserIdParameter".
      + CategoryInfo          : InvalidData: (:) [Add-MailboxFolderPermission], ParameterBindin...mationException
      + FullyQualifiedErrorId : ParameterArgumentTransformationError,Add-MailboxFolderPermission
      + PSComputerName        : ps.outlook.com
  </pre>