Hello there,
I checked your question yesterday but could not find the required info. As there is still no answer I assume that Cisco does not sell this cable.
The normal approach for LRE is to use a single-ended RJ21 and connect the open end to a patch block.
The connector pinout is well described and I have no doubt that you have found it already.
Another option that I can think of is to check with some other cable-vendor. I know that Annixter for example has a lot of custom cables available.
I realize that this is not the answer that you sought but still I hope that you will find it helpful.
Regards,
Leo
