The ornamental design for a sawmillattachment for a chain saw, as shown and described.
FIG. 1 is a top isometric view of the new design for a sawmill attachment
for a chain saw.
FIG. 2 is a bottom isometric view.
A portion of a chain saw is shown in both figures in dotted lines to
illustrate the relationship of the sawmill attachment to the chain saw
which is not claimed.