Yesterday I came across an dll file, wich, when registered in registry, adds import postscript/pdf (requires ghostscript to work) options to MS office/PaintShopPro/Photoline (and other apps that support ALDUS import filter interface)
The zip file came with importps.dll, WEMF.wmf, pdf instructions and mso registry file, wich had this strings:
REGEDIT4

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Shared Tools\Graphics Filters\Import\PS]
"Extensions"="ps pdf"
"Name"="ImportPS: PostScript/PDF import filter"
"Path"="c:\\gstools\\pstoedit\\importps.dll"
;

So, I was wondering is it possible to do that in XaraX, I saw that XNview has file format dll-s in his folder, or, on XNview's webpage http://www.xnview.com/ there is an filetypes sourcecode or dll-s or something (free for noncomercial use), so can it be done in any way?