So that others may help you, here's the link to the marriage record you've mentioned. A subscription to Ancestry.com is necessary to view it, either to Ancestry.ca, or World Access/Ancestry.com.
The marriage in Sheenboro, 1878
http://search.ancestry.com/cgi-bin/sse.dll?indiv=1&rank=...In this marriage record, the parish his parents are from, appears to be Township of Newton "St Justin" in the diocese of Montreal. I believe this is Ste-Justine-de-Newton, Vaudreuil, Quebec.
My best guess about the parents' name scrawl in the marriage record: The father could be Napoleon, and the mother, Sollime (surname could start and L, S, T, or anything else).
There are Beauchamp to be found in Newton and greater Vaudreuil. This is a matter of researching all same surname individuals found in area and putting the pieces together. It's evident this is not a quick and easy search, however the data is there to found. You may have to compile 2-3 generations to make sense of how they relate.
Search every near-by parish by hand, don't rely on the index, as it's filled with error and also incomplete. Look at every record of possible relatives, note witnesses to marriages and godparents to children.
Some parish records in the Drouin Collection on Ancestry.com are degraded and illegible. Always check familysearch.org to find the second copy of the parish record in Quebec Catholic Church Records. Ste-Justine-de-Newton is a good example of the difference you can find between the two sites.
Good luck with your search.