How do I use the NumLock LED to indicate Compose is active in X.org?

Question

I have a Compose key on my keyboard, but use the NumLock key for other purposes whilst using the numpad for entering numbers only. So I don't really need a NumLock indicator, but would like to use this LED to indicate that the Compose key is active. Among the ready-to-use xkb templates I can't find one which would do this job. Here is my xkb/compat/lednum file:

// Use the Num Lock LED to show either
// Num Lock, Group, or Shift Lock state.

default partial xkb_compatibility "num_lock" {
    indicator "Num Lock" {
        !allowExplicit;
        whichModState= Locked;
        modifiers= NumLock;
    };
};

partial xkb_compatibility "group_lock" {
    indicator "Num Lock" {
        modifiers= None;
        groups=All-group1;
    };
};

partial xkb_compatibility "shift_lock" {
    indicator "Num Lock" {
        whichModState= Locked;
        modifiers= Shift;
    };
};

My version of X.org is 7.6 on an openSuSE 13.2 (x86_64) platform.

Can anybody please give me a hint? Thank you.