Notepad++ regex replace

Question

I have text file full of following lines:

F randomtext
F morerandomtext

what kind of regex I need so that the output would be like this:

Answer 1

Find:

F (.*)

Replace all with:

\1,foo

Answer 2

I'd like to add this: With Notepad++ you can find with regex and replace things in a set of files too. The following will find all files which has lines starting with capital F and space in D:\mydir -folder's *.txt files including subdirectories.

To open Find in Files-window in Notepad++ type Ctrl+Shift+F.

Find what: ^F (.*) 
Replace with: \1,foo
Filters: \1,foo
Directory: D:\mydir
Match case: Checked
In all sub-folders: Checked
Search Mode: Regular expression