[cups.general] Center feed Envelope, how to alter ppd?

[Todd And Margo Chester]

Hi All,

I have Google'd my eyeballs out on this with no luck.

I have an Okidata B4350 with a center feed print tray for
envelopes.  When I select #10 envelopes, they prints out on
the left side, instead of the center.

In my PPD file, I have found:

*PageSize Env10/Envelope #10: "<</PageSize[297 684]/ImagingBBox 
null>>setpagedevice"
*PageRegion Env10/Envelope #10: "<</PageSize[297 684]/ImagingBBox 
null>>setpagedevice"
*ImageableArea Env10/Envelope #10: "0 0 297 684"

Can I alter one of these such that I can print in the center?

Many thanks,
-T