I don't know if it is the same for your subject, but for mine it's under "assignments" on the VLE. There is the assignment and a little "view / complete" link underneath the assignment document.
how do you submit your subject specific assignment as it doesn't give you the option on the VLE?
This sounds really silly but when you've clicked on the subject, try clicking on the title (usually the name of the subject)... I had one class where I could never find a link and it was always just a case of clicking the bold title to be directed to the uploader!