Cipboard access in vb.net is made easy with the My.Computer.Clipboard functions.
To put some text on the clipboard you would use the My.Computer.Clipboard.SetText
function.
To read the text you would use the My.Computer.Clipboard.GetText function.
Set the clipboard to some textbox test:
My.Computer.Clipboard.SetText(Textbox1.Text)
Display the clipboard text in a message box:
MessageBox.Show(My.Computer.Clipboard.GetText)
Download the example