This will be worth some more investigation.  I can send a Powershell array of cmd.exe strings to the cmd.exe interpreter and pass cmd.exe a Powershell "here string" that will passthru a Powershell variable to the cmd.exe interpreter. Be interesting to next see if I can reverse the process.

# writes out time and date from cmd.exe

write "Time and Date from CMD.EXE:" 

$Global:command = 

"time /t",

"date /t"

out-file -inputobject $command -encoding ASCII -filepath $pwd\cmd.txt

Start-Process cmd.exe -argument /Q -nonewwindow -wait -redirectstandardinput $pwd\cmd.txt