The ornamental design for a portion of a packagingcontainer, as shown and described.
FIG. 1 is a front, side perspective view of a portion of a packaging container according to our new design, the rear, side view being a mirror image thereof.
FIG. 2 is a side elevational view thereof.
FIG. 3 is a rear, side and bottom perspective view thereof.
FIG. 4 is a side elevational view, the other side being a mirror image thereof.
FIG. 5 front elevational view, the other side being a mirror image thereof.
FIG. 6 top plan view thereof; and,
FIG. 7 bottom plan view thereof.
The portion of the packaging container illustrated in broken lines is for environmental purposes only and forms no part of the claimed design.