The ornamental design for a cover of a cord-guiding device for a window blind, a shown and described.
FIG. 1 is a perspective view of cover of a cord-guiding device for a window blind showing my new design,
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof; and,
FIG. 8 is a perspective view of FIG. 1, showing the design positioned to indicate the direction of placement of the design upon a window blind head rail when in use.
The broken lines in FIG. 8 showing a window blind, head rail, and a second cover of a cord-guiding device depict environmental subject matter that forms no part of the claimed design. The broken lines leading from the cover of a cord-guiding device for a window blind to the head rail indicate the direction of assembly of the design in use and form no part of the claimed design.