<p>I want to create cursor rsrc files on the Mac from png files. The application that uses the cursors requires it to be in a .rsrc format and I cannot change that. Does anybody know of any way I can create the cursor .rsrc files from png images.</p>

Its been a long time since I've thought about MacOS resource forks. Are you using the classic MacOS (i.e. before MacOS X)?
As I recall,
ResEdit
was the application most often used to manipulate the resource fork of a classic Mac application. I know it can edit cursor resources, but I don't recall if it can read PNG files. You may need to convert the files to GIF.
ResEdit is a Classic MacOS application. MacOS X prior to 10.5 could run Classic apps in emulation, but in 10.5 this support has been removed. You'd need to find a system either running the classic MacOS directly, or running 10.4 with Classic installed.