How to change a cell to exact text (for advanced filtering)

Hi everyone, first post!

Ok, here is my dilemma. I have a large advanced filter list to find names paired with dates to get further information from a large list (over 20,000 rows!). I need all my text strings in the criteria range to be in the format of ="=text string" (or so I believe) in order to get an exact match. Is there anyway to change all the text to the required format in an easy way instead of manually doing it? I tried to write a macro to do this but It kept changing the name of each cell to the test names I used when writing the macro.

Anyone have any ideas? I am stumped