Your question does not make much sense. The PCI-6250 is a data acquisition board with analog inputs and some digital I/O. It is not designed to control a voltmeter if by control you mean command a meter to, for example, set a range and take a reading. If the meter has a serial port connection, you connect a serial cable between it and the pc. If it has a GPIB connection, you buy a GPIB controller and connect the controller to the meter. What exactly is the make and model of the meter you're trying to control?
