IO redirection or wedge or VSP

I am using some cross-development tools running on cygwin. I have two
utils, one is a terminal-cli type program which talks to the target via
a jtag interface, and one is a debugger which expects to talk to the
target via a standard serial port. No source exists for either one. I'd
like to redirect the IO such that the debugger sp uses the jtag
interface with something like:
%jterm<>vsp(debugger)&

The '<>' is supported in at least one shell (amigaOS I believe). Is this
type of redirection possible in any of the common shells? What else do I
need? virtual sps, a KB wedge?

tia