EMPLOYEE WAS ASSISTING 2 OTHER REPAIRMAN INSTALLING A BALL MILL ACCESS DOOR. A CRANE WAS BEING OPERATED BY ONE OF THE REPAIRMAN TO LIFT THE DOOR INTO POSITION. EE WAS HELPING TO GUIDE THE DOOR INTO POSITION WHEN HE INADVERTANTLY PLACED HIS HAND ON THE CRANE CABLE BLOCK. HIS LT. FINGER GOT CAUGHT BETWEEN THE CABLE & SHEAVE ON THE CRANE BLOCK. CUT & FRACTURED LT. PINKY FINGER.