To keep from splitting a specific word in a specific place, insert a discretionary hyphen (on a Mac, command-hyphen) at start of that word. The discretionary hyphen won't get used (because the word won't split) and the word won't split (because the word could only get split on the discretionary hyphen). This has worked for me on Quark 3.3 and 4.11, and I would assume version 5 as well.