The church probably has copies of the churchbooks, but they should also be at the at the Kirchenbuchamt Hannover in Hannover on Hildesheimer Straße. They do not do research for others, but you can go there and do research. You can write them to verify that that church's records are held there. I have family in this area too and I imagine if my parishes are there, so would this church. Their url is:http://www.kirche-hannover.de/kirchenbuchamt/index.html
I have never tried writing in English, but Birgit Klein is the person you would ask. Her email address is on the site. It has been a few years since I have visited this center.
I have some friends from Stöckse and Steimbke perhaps if that doesn't work. You can contact me offline about that as I have never inquired if they would be interested in doing research in the church records for anyone, but I could ask.
Good luck with your research!