The ornamental design for a neckcover with a pocket, as shown and described.
FIG. 1 is a perspective view of a neck cover with a pocket.
FIG. 2 is a front elevation view of the neck cover with a pocket.
FIG. 3 is a back elevation view of the neck cover with a pocket.
FIG. 4 is a left side elevation view of the neck cover with a pocket.
FIG. 5 is a right side elevation view of the neck cover with a pocket.
FIG. 6 is a top plan view of the neck cover with a pocket.
FIG. 7 is a bottom plan view of the neck cover with a pocket.
FIG. 8 is a front elevation view of the neck cover with a pocket attached to a hat.
FIG. 9 is a back elevation view of the neck cover with a pocket attached to a hat.
FIG. 10 is a left side elevation view of the neck cover with a pocket attached to a hat; and,
FIG. 11 is a right side elevation view of the neck cover with a pocket attached to a hat.
The dot-dash lines define the bounds of the claimed design and forms no part of the claimed design. The claimed design extends to the dot-dash boundary line. The dot-dot-dash lines in FIGS. 8-11 illustrate the environment of the neck cover with a pocket and form no part of the claimed design. The dash-dash lines depict portions of the neck cover with a pocket that form no part of the claimed design.