Uses Apply Image on a Mask within a pre-preprocessing script

psApplyImgMask.jsx

function psApplyImgMask(sourceName,destName){
    cTID = function(s) { return app.charIDToTypeID(s); }; 
    sTID = function(s) { return app.stringIDToTypeID(s); };

    app.activeDocument.activeLayer = doc.artLayers.getByName(destName); //variable must be string
    
    var descAIM1 = new ActionDescriptor();
        var refAIM1 = new ActionReference();
            refAIM1.putEnumerated(cTID("Chnl"), cTID("Chnl"), cTID("Msk "));
    descAIM1.putReference(cTID("null"), refAIM1);
    descAIM1.putBoolean(cTID("MkVs"), false);
    executeAction(cTID("slct"), descAIM1, DialogModes.NO);
    
    var descAIM2 = new ActionDescriptor();
        var descAIM3 = new ActionDescriptor();
            var refAIM2 = new ActionReference();
                refAIM2.putEnumerated(cTID("Chnl"), cTID("Chnl"), cTID("RGB "));
                refAIM2.putName(cTID("Lyr "), sourceName); //variable must be string
        descAIM3.putReference(cTID("T   "), refAIM2);
        descAIM3.putBoolean(cTID("Invr"), true);
        descAIM3.putBoolean(cTID("PrsT"), true);
    descAIM2.putObject(cTID("With"), cTID("Clcl"), descAIM3);
    executeAction(cTID("AppI"), descAIM2, DialogModes.NO);
}