RGetResource
RGetResource Read a resource; get its handle
#include <Resources.h> Resource Manager
Handle RGetResource(rType, rID );
ResType rType ; Resource type, (e.g., 'FONT')
short rID ; ID of desired resource
returns a handle leading to resource data
This works just like GetResource, except that it searches for the specified
resources among all open resource files before looking in ROM.
rType is a 4-byte ResType value. It identifies the resource type you want
read into memory (e.g., 'FONT', 'WIND', etc.)
rID is the resource identifier, as defined in the resource file. For
application programs, the convention is to use positive values higher
than 127.
Returns: a handle leading to the resource data. A return value of NIL indicates
an error - either the resource can not be found or it will not fit into
memory. See ResError.

Notes: Please refer to GetResource for detailed information. RGetResource
works with the Mac Plus, as long as it's using at least System 4.1.