Crystal Reports and printing

I've just finished a project using VB and CR, and I'm at a loss to optimize a routine that takes way too long to print.

In short, I have a vb program that chooses to print one of 4 reports, an english invoice, a french invoice, an english statement or a french statement. The problem is that the VB program calls Crystal each time which slows the process down immensly. Is there a way for me to have CR running as I pass it my parameters(the invoice/statement to print)? So, for 20 marks, how can I do this? :)

Thanks in advance