I need to programmatically redefine a named range (normally created On the
Insert menu, point to Name, and then click Define. Type the name e.g.
MyTable, select the range and then click OK.) in an excel file.
I need to change the range from e.g. A1:D18 to A1:D1.

How can this be done in C#? If you don't know C#, VB is ok too.