Filling a window sill


Here's a photo I took of it half an hour ago:
http://tinypic.com/view.php?pic=1z6fhhl&s=4

Between the wood and stone could I use readymix patching cement?

Or would i be better with something more flexible like brown window sealer
from a tube?

Or would car body filler with wooden blocks inside it be better, when I find
a cheap source?

Or why not fill it with expanding foam then put a waterproof skin of car
body filler and then paint on it,
then i could fill every gap inside it whereas squeezing in bodyfiller could
leave gaps..


There was a wooden beading at the top of the wood,
but it seems to me an invitation for water to seep down the back of it
so i am planning on not replacing it.


(the weather man says 4 out of 5 sunny days coming up...)
--

[george]