"van" can mean "from", but also "of", "belonging to" or even very generally "somehow related to". Based on the spelling, I would guess that the name originated in the Dutch-speaking part of Belgium (it's old spelling; in the Netherlands, names tend to be 'modernized', in this case to "van Haak", while in Belgium, they have kept the older spelling), but it might also be from the Netherlands.
"van Haecke" literally means "of the hook". Where that comes from, I can't say. Maybe a fisherman, maybe somebody with a hooked nose, maybe captain Hook ;) . As far as I know, there's no place called Haecke, but I don't know all places.
In the Netherlands, the rule is to not capitalize prepositions (so "van Haecke"), but in Belgium, the rule is the follow the way it was written in the birth record. Before roughly 1800, however, spelling of names was not standardized. Unless you're sure the name was used in Belgium after 1800, the safest guess would be to not capitalize.
Do you have more information about the person that you're interested in?