Excel Get_Range with multiple areas

I'm trying to get a range from Excel, which has multiple areas specified, essentially I've got...

int StartColumn
int EndColumn
int[] ColumnsToSkip

When you combine these it's possible to produce a range with non-contiguous areas. Unfortunately I can't quite figure out the call to get this... MSDN isn't very useful...

WorkSheet sheet;

sheet.get_Range( what goes in here??? );

Anyone provide any help? Cheers.