This surname doesn't seem to feature in baptisms in Kent around the relevant timeframe.
Looking at some online trees suggests the name could be Dutch.
I don't know if this relates to the Cornelius Mulder/Maulder you are looking for but thought I'd post just in case.........
Cornelius Meulders (Evers)
Baptism Date: 19 mei 1770 (19 May 1770)
Baptism Place: Bergen op Zoom, Netherlands
Role: dopeling
Register Type: doopakte
Archive: Het Markiezenhof
Cornelia Meulders
Baptism Date: 15 mrt 1776 (15 Mar 1776)
Baptism Place: Steenbergen, Netherlands
Role: dopeling
Register Type: doopakte
Archive: Het Markiezenhof
details from Anc*y
Web: North Brabant, Netherlands, Markiezenhof Baptism Index, 1597-1810There's also these 4 Cornelius Mulder
Netherlands, Baptism Index, 1569-1907 unfortunatley I can't view details ie location, dob only the persons name & parents
Cornelius Mulder Jan, Anna
Cornelis Mulder Hendrik, Neeltje
Cornelis Mulder Reinier, Catharina
Kornelis Mulder Jan,Jannetje
you can also search marrriages
Netherlands, Marriage Index, 1570-1938