Hello Lois Peschel,
write to the
Landeskirchliches Archiv Hannover
this is the Central Archiv for the Evangelical-Lutheran church of Hannover.
They had microfilms or fiches for the churchbooks from the beginning til
1852 and some also til 1875. For the churchbooks there exists alphabetical
registers, some computer based.
I hope this helps.
If not there is a mailing-list: Hannoverfirstname.lastname@example.org