How can I do this shadow effect?

there is a plane which is semitransparency in front of the object, and a light source behind the object, how can I draw the project-shadow on the plane which can be seen
in front of the plane?

Look up “projective texture mapping”. Note that you’ll need a user clip plane, else objects between the translucent plane and the light source location will also, erroneously, have the image projected onto them.