space after prefilled text-area

inside a text-area i got a prefilled text ( no placeholder text ) – so if the user opens that page and tries to enter some text the cursor will start from that end of the text. The user can erase that prefilled text – but clicking inside that text-area he can start from that prefilled text.
How do i enter a space after that prefilled (default) text. Yes   works but that character are first seen before they will show the space. A %20 does not work.