I would suggest the author to consider MSN money as a source of data. Microsoft now already incorporate quote from MSN money into Excel. It is pretty easy to get a real-time quote, exchange rate, and historical data directly in Excel (one problems, however, is dividend. There is no way to get dividend data from MSN at this moment. We may still need to rely on Yahoo).
Another reason I suggested MSN money is that it is probably the only reliable source for Canadian mutual fund data. Yahoo has it. But they do not update their data regularly.
As for the data source, I also suggested author to look athttps://investexcel.net/multiple-stock-quote-downloader-for-excel/
those allows people to directly download Yahoo finance quote and the dividend information. If you can cooperate with the author to incorporate those into your Excel file, it will be fantastic. Alternatively, you may make portfolio slicer using the data downloaded into the two Excel files that the website provide. It will be easier to use than the script