Assignment

Hi all,
In the moodle , On the course page i.e (/ moodle/course/view.php) it is displaying all the assignment when we click on any assignment it either ask to upload upload assignment to student or it displays the assignment if student already submitted their assignment. Same for the Teacher it displays the evaluated assignment if it is there.

But i want to make some modification on the course page i.e (/ moodle/course/view.php) page where all the assignments are dispalying.
I want to Put 4 links i.e. upload assignment , download assignment. (for Student) UPload Evalution , Download Evalution (For Teacher). All these 4 links i want to put in the course page . When uses click on the "upload assignment" It will allow the user to upload the assignment which is already there. But if it is already uploaded then it should be downloadable. Same for "UPload Evalution" , when clicked it should allow teacher to upload the evalution and if it is already evaluated then "Download Evalution" link should be active. For the Student Upload Evalution link should not be active same for the tecaher "upload submission " link should not be linked.
I am also attaching the Format that it should look like. May be it should give the clear picture.

Pls Let me know the solution .
Thanks
Ashok Naidu