I looked through our Instrument Driver Libraray, and was able to find a LabVIEW driver for the HP E1326A, which may be adaptable to your instrument. You can find it at:
http://zone.ni.com/idnet97.nsf/9b2b33e1993d877786256436006ec498/4c6df17e44fa427c862568ab005fbb97?OpenDocument
or you can visit our Developer Zone at zone.ni.com to see if you can find another close match. Also, you should check with HP to see if they have a LabVIEW driver built for their instrument.
Ryan Tamblin
Applications Engineer
National Instruments