If I had to take a stab at it I'm guessing the two a's on top and bottom are the same octave. So from standard tuning you would go up in pitch on the low e to make it the same as the standard A. The F# is down a half step from normal so you could match it to the 4th fret on the D string. Then for the a on the next string match it to the 2nd fret on the F# and for the last one go up until you match pitch with the a above it. That might work but it seems a bit complicated. What song is it may I ask?