You can do a rectangle selection (alt+drag) over the area to the left of the characters to be indented. In the example shown you could select one space wide by three high just left of the three 'f's. (You could also select a rectangle zero characters wide by three high.) Then type space characters until the three lines are correctly indented. When you type into a rectangular selection, the same character is entered into each line.
This does not align ragged text but it may make it quicker to align things. Another speed up with many lines currently having a ragged left is to align groups of adjacent lines one by one, then select a rectangular area and type space to align that.
(Checked in Notepad++6.3.2.)