qmake: QMAKE_EXT_CPP_MOC and QMAKE_EXT_RES not working

It seems to be impossible to change the file extension for moc files, but leave the qrc files as they are.

The use case is as follows:

• change moc "filename.h" to "filename.moc"
• leave rcc "filename.qrc" as it is "qrc_filename.cpp"

the QMAKE_EXT_CPP_MOC and QMAKE_EXT_RES looks like to be the ones to use, but those seem not to have any effect.