A DOUBLE thanks to you; because this faux pas by me is not going to cause a loss of anything but peoples' time, it seems.
On this morning, at this address of Blockchain.org
https://blockchain.info/address/16ckC8g6BkUDoJPXi1VxvfC41ift4LwQ1Z , there is shown a credit of "0.099044 BTC". However, this is the address given me by the QuadrigaCX computer (for use with BCH --- 16ckC8g6BkUDoJPXi1VxvfC41ift4LwQ1Z). So QuadrigaCX staff have access to its private key, and I have sent them a note telling them that I am on my knees begging them to put the funds back into my BTC account at their exchange. (I will get back to them for help re. crediting the 0.099 BCC to my BCH account, later on -- so thanks again here.)
There is a silver lining here (even if I end up losing the money).
I am not a computer neophyte but I just started buying cryptocurrencies (coming over from years of options trading in the stock market), and the one thing that has bothered me most is the fact that there is no one ("at the bank", so to speak) call and ask to track down the misplaced money and reroute it to the right place. (It still bothers me!) But this record keeping at blockchain.org is just super, and I am sure that if more people in the huge horde of potential crypto. traders still waiting to 'join the club' knew about what this service at blockchain.org achieves it would lower their anxiety level a lot, as it is now doing for me.
Cheers!