[plt-scheme] MysterX and ImageMagick COM object

Hi,

I've been trying to use the ImageMagick COM object for
manipulating images.  (See www.imagemagick.org.)
It works in VB, but in DrScheme I get a complaint
about the arguments.  In VB I use

  dim im as ImageMagickObject.MagickImage
  set im = new ImageMagickObject.MagickImage
  im.convert("C:\\arf.bmp", "C:\\arf.jpg")

In DrScheme I try
  (define im (cci/progid "ImageMagickObject.MagickImage"))
  (com-invoke im "Convert" "C:\\arf.bmp" "C:\\arf.jpg")

  com-invoke (method "Convert"): expects type <com-0x401b> as 3rd 
  argument, given: "C:\\arf.bmp"; other arguments were: #<com-object>
  "Convert"a "C:\\arf.jpg"

0x401b is a VT_SAFEARRAY, so I guess I need to know how, if possible,
to create that in DrScheme.

Thanks,

Ron