Hi JFB. I am an Excel user like you.
I have had to deal with this problem before. I get around it as NLtL indicated by dragging it without the quotes and then using Replace to fix the quotes. When you drag the formula it may error with #REF, that's OK.
But, in order to edit the formula with Replace you must first fix it so that Excel doesn't recognize that it is a formula or it won't let you edit it in pieces like you need to. I do this by changing the = sign at the beginning of the formula to something random that I can change back when finished. It must be something that cannot appear anywhere else so I usually highlight the column (or formulas) and use Replace "=" with "red=" and click Replace All. Now The string doesn't begin with the = sign so Excel doesn't treat it as a formula.
Now use Replace to replace the ( with (" and then replace the ) with "). When you have those complete replace all of the "red=" with = sign again and you are back in business.
Reply if you have additional questions or more information. Please mark this reply as answered if this solves your question.
Rich~M