Tie fish line to it, thread the fish line through pulling the cord with it, then cut the fish off. 1 Alex, Assuming I know the type of cord you are talking about, try taking a large paper clip and making it as straight as possible. The use it to push the cord thru on the one side and pull it back up on the other. Works for me. I use the awl that I use to string my racquets with.
Some people use paper clips.
Anything that has a point that you can push it under the bar and then pull should work. Takes about 2 seconds. Now, put the end back into the handle, and keep pushing straight down until it's 'jammed' lightly. Don't worry about 'making the turn' under the post. Next, bend a paperclip straight, but with a slight hook on the end.