I added a custom resource to my applications resources called "MESH" and inserted a directx file IDR_MYMESH (mymesh.x).
Then I created a D3DRMLOADRESOURCE:
myResource.hModule = NULL;
myResource.lpName = MAKEINTRESOURCE(IDR_MYMESH);
myResource.lpType = "MESH"
then I called the meshbuilder load method:
myBuilder->Load( &myResource, NULL, D3DRMLOAD_FROMRESOURCE, NULL, NULL);
The problem seems to be that lpName isn't receiving the IDR_MYMESH resource name. It contains "".