QProcess problem in accessing stdout

how to handle the user input action in our application
i am using QProcess for starting the process but not getting
completed because the command need user name and password.
The code is like this

QDir::setCurrent("d:\\VSS\\win32");
sourceControl=new QProcess(this);
sourceControl->start("ss Get TDS_PR1.xml \"-O&File.txt\"");
if(sourceControl->state ()==QProcess::NotRunning)
QMessageBox::warning(this, "Application name here","not running");
else if(sourceControl->state ()==QProcess::Starting)
QMessageBox::warning(this, "Application name here","Starting");
else if(sourceControl->state ()==QProcess::Running)
QMessageBox::warning(this, "Application name here","Running");

can anybody help