The ornamental design for a handle for a screwdriver, as shown and described.
FIG. 1 is a perspective view of a handle for a screwdriver showing my new design;
FIG. 2 is a front elevational view thereof
FIG. 3 is a rear elevational view thereof;
FIG. 4 is an enlarged right side elevational view thereof;
FIG. 5 is an enlarged left side elevational view thereof;
FIG. 6 is a bottom view thereof; and,
FIG. 7 is a top view thereof.
The broken line showing of the screwdriver blade is included for the purpose of illustrating environmental structure and forms no part of the claimed design.