How to add .fm files to existing book using ExtendScript ToolKit

I've updated my code with a

var book = app.ActiveBook;

And your function to add book components

function addBoilerPlate(book, componentPath) {
    
bookComp = book.NewSeriesBookComponent (0);   
// Move it to the end.   
if (bookComp.NextComponentInBook.ObjectValid()) {   
    bookComp.NextComponentInBook = 0;   
} // Set its path.   
bookComp.Name = componentPath;
bookComp.MoveComponent(1);
}

By itself your function adds the boilerPlate.fm to the end of the book.  However, I want it between the title and TOC.  Once it is added I can move it up with bookComp.MoveComponent(1); but the final version of this script will deal with books with different numbers of chapters so that wont work.  Is there a way for me to add boilerPlate.fm between 2 specific pages or after or before a specific page?  I tried modifying the 0s in your function, but no matter what I did it always added boilerPlate.fm to the end of the book.

Full code:

var sourceDoc = openXmlFile("Absolute path to ditamap");
var path = "Absolute path to output";
var componentPath = "Absolute path to boilerPlate.fm"
saveToFm(sourceDoc, path);
var book = app.ActiveBook;
addBoilerPlate(book, componentPath);
function openXmlFile(filePath) {  
    var file = File(filePath);
    var fileName = file.fsName;
    var openParams = GetOpenDefaultParams();  
    var retParams = new PropVals(); 
    var doc = Open(fileName, openParams, retParams);
    return doc;  
}  
function saveToFm(fileObject, savePath) {  
    var saveParams = GetSaveDefaultParams();  
    
    var i = GetPropIndex(saveParams, Constants.FS_FileType);  
    saveParams.propVal.ival = Constants.FV_SaveFmtBookWithFm;
    
    var i = GetPropIndex(saveParams, Constants.FS_DitavalFile);  
    saveParams.propVal.sval = "Absolute path to Dita Val File"
    
    var saveAsName = savePath;  
    var returnParamsp = new PropVals();  
    fileObject.Save(saveAsName, saveParams, returnParamsp);  
}  
function addBoilerPlate(book, componentPath) {
    
bookComp = book.NewSeriesBookComponent (0);   
// Move it to the end.   
if (bookComp.NextComponentInBook.ObjectValid()) {   
    bookComp.NextComponentInBook = 0;   
} // Set its path.   
bookComp.Name = componentPath;
bookComp.MoveComponent(1);
}