Springiness question...

I am trying to build a very simple system with a single chain (rope
like) and I simply wish to stretch the system between two bodies.

from
[]vvvvv[]   <--- crude schematic
to
[]----------[]   <--- crude schematic

My problem is that no matter how I set the ERP or the CFM, I can't
find a setting that allows me to have a chain that behave like its
unstretchable...
I always end up with something like this in the end....

[]  -  -  -  -  -  -  -  -  -  -  []   <--- crude schematic (again)

I know an unstretchable chain might be unstable, but I will try nonetheless...

Else is there any solution? Should I add an opposite force to balance
the stretching force?

Thanks