insert chars in selected columns

Hi,

i want to insert chars (blanks, etc) in each line on a certain position. I mark the columns with the selection mode "column" then i press the char but the char is only inserted in the fist line and not in all selected lines.

Example:

Before:
12345
12345
12345
12345

Inserting a blank after 123
After:
123 45
123 45
123 45
123 45

How can i do this?

thanks!

Use Insert text to lines (Alt+I) or menu Edit.