As you've probably realized, when you type a '%' character, SQL Search always interprets it as a wildcard, including in 'Exact Match' mode.
However, I'm not sure why this would be a problem for you, because wildcard '%' will match the literal '%' character.
So, when you search for 'ProductN%', that should give the result you want (although there may also be other results for 'ProductNumber', for example, since this would also match 'ProductN%').
I hope that makes sense. If it isn't working as I've described, please let me know here, including which version of SSMS and Operating System you are using.
Red Gate Software.