I am not sure what you describe? Since it''s a
line it could have a rope loop or a thimble. As mentioned chafe must be condsidered. This is by far the main cause of boats breaking off their moorings. I have seen four of them so far and helped rescue three of them.
If the thimble is steel then you should use a steel shakle to attach to it. If it''s smooth plastic then just rope on a temporary basis would work overnight.
I saw a "expert" who was a boat broker send a
line thru a steel mooring eye in Stage Harbor, Chatam, MA. The boat was a huge 56'' Winnebago type and we got hit with a 50 knot storm. The
line sawed thru, he started the engine and tangled one of the screws in the mooring chain of a OI 41 and layed backwards to the wind alongside of it. I called the CG and they came out but by that time the wind was down.
Chafe very bad.