how to force tty / input to be assigned , to a & backgrounded process , for fg just after varpid=$!

[alex xmb sw ratchev]

there is a program , that when given no args , it goes into stdin mode
in input mode , also in output mode , comtrol - c is used by this app , for
like abort-output-and-continue-input

for this i gotta know the pid , to send int to

so cmd & pid=$! ; fg

my q is should i add something </dev/stdin to cmd ? to be ' more sure ' ?

greets