The ornamental design for a pickuptruckboxcoverexterior surface, as shown and described.
FIG. 1 is a top plan view of a pickup truck box cover exterior surface
showing my new design;
FIG. 2 is a right side elevational view thereof, the left side elevation
being a mirror image of the right side elevation;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a front elevational view thereof; and,
FIG. 5 is a perspective view thereof with broken lines indicating adjacent
portions of a truck box and a truck cab being for illustrative purposes
only and forming no part of the claimed design.