setting paper size in VB code to use Crystal Report Design

I am using VB 6 and Crystal Reports 9.2 . I have created a report in CR and have written code in VB to call that report. In this VB code I have to define paper size etc. I want to print in DOT Matrix Printer in 8 x 6 inches stationery. I am trying to use :

rpt.papersize = cruserpapersize
rpt.setpapersize x,y

(here I want to define 8 inches by 6 inches)

What I have to write here? In the help it is written that length and width will be in pixels. What is the relation between pixel and inches. What is the conversion factor.