Lookup In "Split" Ranges As In One

I have a situation. I need to perform a HLOOKUP and, let's say, find a Top 5 largest values in a row. The issue is that my data is structured something like this:
A B C D E F G H I J K L
# # # S # # # S # # # S ...etc

Each # is a numeric value, and S are their sums. Needless to say that I don't want to do a lookup in the whole A:L range, since sums will show up as top values. So what I want to do is to perform a lookup ignoring the sums, meaning in ranges: A:C,E:G,I:K. So it's like making a new "unified" range out of several small pieces. But this should be done within one formula, of course.

Is anything like this possible by any chance, guys/gals?
Thanks so much in advance!