i would like to know as well,,,
my wire did not break but the black clip that holds the wire in the lil hole is chipped and giving way
where did your cable break?
but here is an alternative that might work for you that just popped into my head
go to your local bicycle shop and get some brake cables , feed it thru the same housing if not,,use the one provided at the bike shop,,look around the shop and at all the cables and accessories and see whats your best option and im sure with the proper nuts and bolts or maybe even some brake adjuster barrels used on bikes you can get it done,,,put some thought into it and im sure it can be an easy weekend fix