Say I have this data in a Google Spreadsheet:
cat cat mouse mouse mouse cat dog dog
And I only want to apply conditional formatting to the ones in brackets
 (so I can hide them but still calculate with them)
cat [cat] mouse [mouse] [mouse] cat dog [dog]
How do I do it? Merging cells won't work because the data needs to be entered line by line and I don't see the option in conditional formatting or when searching around the web.