The ornamental design for a vehicledoorwindowsillsupportbracket, as shown and described.
FIG. 1 is a perspective view of the vehicle door windowsill support
bracket. The broken lines showing of the interior of a vehicle door in
FIG. 1 is for illustrative purposes only and forms no part of the claimed
design;
FIG. 2 is a top plan view thereof, shown at an enlarged scale;
FIG. 3 is a front view of FIG. 2; and,
FIG. 4 is a side view of FIG. 2.
The bottom and rear surfaces of the support bracket form no part of the
claimed design.