Column/rectangular selection is dragging a rectangular selection frame over the text (for example with Visual Studio with Alt+Drag) and only select that text without selecting entire lines.
Is there any control for WinForms / WPF with that capabilities?
The Winforms Textbox, RichTextBox and WPF Textbox, RichTextBox don't provide this functionality.
The code editor controls like AvalonEdit or Scintilla.NET also don't know about this (I maybe wrong, but their documentations do not mention such things).
The AvalonEdit control indeed has a column / rectangular selection mode. They didn't seem to care about mentioning that, but using the appropriate control ICSharpCode.AvalonEdit.TextEditor either inside WPF or an ElementHost inside a WinForms application does the trick.