The ornamental design for a supplementarytool handle, as shown and described.
FIG. 1 is a front, top and left-side isometric view of the supplementary tool handle of the invention;
FIG. 2 is a rear, bottom and right-side isometric view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a left-side elevation view thereof;
FIG. 5 is a rear view thereof;
FIG. 6 is a right-side elevation view thereof;
FIG. 7 is a top end view thereof;
FIG. 8 is a bottom view thereof; and,
FIG. 9 is a front, top and left-side isometric view thereof with a screwdriver shown in broken lines and representation of environmental subject matter.
The broken lines in FIG. 9 illustrate environment and form no part of the claimed design.