As I read that you need to include quote characters inside the quoted string of text in your expression. To do that, put a \ character in front of each such quote character. This is called the "escape" character.
Let me recap to make sure I understand. I put quotes around everything I want to ignore and \ just before the quotes that are inside that group of stuff to ignore.
I think that works on my little test! Just want to be sure I have it fully understood.
Thanks so much!
Yes, the reason it wasn't working in your original attempt is that left quotes that enclosed your substring were perceived as the right quotes that ended the section of quoted text. FileMaker is then looking for operators, variables and field names and returns an error when your sub string doesn't fit that syntax. Putting the \ in front of quotes tells FileMaker to treat that character as any other character in the quoted string instead of as the quotes that close off the string of quoted text.