Notepad++ How to paste string across multiple lines

Question

Alt+Shift+DownKey to box-select beginning of each string followed by Ctrl+V pastes only on the first line.

Expected behavior: paste my string on all selected lines.

Using Notepad++ v5.9

Answer 1

1) Mark

2) Push Alt+c to open Column editor

3) Enter text there

EDIT

As commented by @chapo it now works fine with Alt-Shift-Down and then pasting.

Answer 2

Can you select your column with Alt+Shift+Down, type in a single unique character then use Search+Replace to get your text inserted the way you want?