[AUCTeX] preview-latex with pdftex and a pdf2png tool

[David Reitter]

Hi,
I've found this little tool that will convert pdf to png for me.
How would I go about telling preview-latex to use the tool to convert  
the PDFs generated (when using PDF Mode) to PNGs?

I've had a quick look at "Preview Gs Image Type Alist", in particular  
the dvipng entry, for which the appropriate info page suggests that  
this is what is used to convert PDF to PNG. Here, however, I can only  
set some Ghostscript options - but GS is exactly what I'd like to  
avoid by using my own pdf2png tool.

I'd be most grateful to someone who could set me on the right track  
here...