Printing on custom size paper-HP Laserje

I am trying to print addresses on our custom size address labels (4×61/2″) that I use on 9×13″ and 10″x12″ envelopes. I am using a Hewlett Packard Laserjet 4Plus. I can do this in Word 2000 but have been unable to adapt other software such as Crystal Reports and our custom database software. I have tried to use another size designation such as Envelope DL and place the text accordingly to get what I want, but then the printer prints the first correctly then prints a blank second. This makesthe 2nd gray with toner residue and is a pain when I want to print hundreds of address labels. Any suggestion on how to adapt?