I use this code to load a .Net assembly to PowerShell:
[System.Reflection.Assembly]::Load(\"System.Windows.Forms, Version=2.0.0.0, Culture=neutral, Publ
You can store the type in variable and use the variable
$forms = [System.Windows.Forms.MessageBox] $forms::Show('Hello')
And in this case you can load the assembly like this:
Add-Type –assembly system.windows.forms