Unfortunately, not as a separate item. You can see from the S2718H/S2718HX User's Guide pages 5/6 that the speaker DIN cable is not a separate item. The speaker and DIN cable cannot be purchased. The speaker and its attached DIN cable ship with the entire monitor. For my notes, send me via Private Message the S2718H service tag number. Did you somehow disconnect the cable from the speaker and lose it?
Understood, but no. There is no mention of a DIN cable extender in the manual nor in our parts page.