I suspect you may have to put the camera on a tripod
(or equivalent
means of keeping it fixed) and take something like a dozen
pictures and
then digitally average them, to get the equivalent of a long exposure
with a slow film.
Little bit of a problem with that logic...you would want to "accumulate" or
"sum" the light from shorter exposures to simulate a longer one, not
"average". And if the light is low enough you could end up summing a bunch of
"0"'s in any case....