The ornamental design for a portion of an electronicmouse, as shown and described.
FIG. 1 is a rear perspective view of a portion of an electronic mouse showing our new design;
FIG. 2 is a front perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof; and,
FIG. 7 is a top view thereof.
The broken line showing of various regions and the unshaded areas therein is for illustrative purposes only and forms no part of the claimed design. The broken line showing of the remainder of the electronic mouse is for illustrative purposes only and forms no part of the claimed design.