Extracting Resources from MacOS X Resource Files

[Dave]

Hi,

Is there a way I can extract resources from a MacOS X .rsrc file?  
(e.g. a Theme file). Specially I have a resource file that has a  
number of "icns" resources and a number "png" resources that I'd like  
to extract into separate ".icns" or ",png" files.

Thanks in advance
All the Best
Dave