Hmmmmm.

I found this on the net; the author plainly states it's a bit of a hack, but also claims to have made it work for him. I've not been able to get this to work myself.

#Pass the Y and exit

$PlinkCommand = [string]::Format('echo y | & "{0}" {1} exit',

$PlinkAndPath, $plinkoptions )

Write-Host $PlinkCommand

$msg = Invoke-Expression $PlinkCommand

Where

$PlinkAndPath is path to .exe, and

$plinkoptions are the parameters (username, password, hostname, etc)