Gonna have a character going Startoss, Ricochet Toss, Rapid Shot, etc. So really they don't need this kind of an item, but I wonder if it exists. Beyond the answer of "returning weapon".
There's a practical use of course, getting thrown weapons back prior to Ricochet. However there's also the chance of running into something with Snatch Arrows. If my magic dagger is caught by the enemy, the look of abject horror on my character's face will be priceless, but the option to tug it back to me should my feats fail me just seems like a semi-cool thing.
So the range increment on a dagger is 10ft, 15-40ft for a Flying Blade, for a potential of up to 200ft assuming a max-level Startoss Shower. Does this cord exist?
Not that I know of. There is a rope dart, but that's a different weapon entirely. The called magic weapon property works also.