Not logical, but if you picture the symbol, quite easy to guess :)

Even knowing what the symbol looks like, I'm having a difficult time just getting started. Anyone willing to give any hints?

3 years later, solved it no problem. Just referenced the symbol from google.

The bottom 3 start in C9. You should be able to solve it no problem from there with reference of the symbol. If not, here's some more hints:

R1:C7. C1:R9, and C12:R12.

Thank you hints. Could not have done this without them.

Googling the Leo symbol also helped me solve the puzzle without hints: ?

Start with the 3 in the bottom row.

Oops, in the last comment, the ? is supposed to be the Leo symbol.

Squashed and misshapen, but i got there, thanks leradraco69.