If you have that many records then I am assuming they are in database format, in
which case if you have Access you could dump them in there and then query them
from Excel with a Pivot Table or just an ordinary MSQuery. You may even be able
to query them from Excel right where they are now, but it depends on where they
are stored.
Really depends what the data is and what you want to do with it, or get out of
it.