First, you need to evaluate and determine if this is a win for White or not? If you think it is, what is the plan? One way or another, this would require analysis of 40-50-60+ moves.
This is pretty way beyond my abilities to fully analyze, but if it is winnable, the first move has to be to bring the white queen as far up the board and as close to the black king as is possible, then bring the white king up using the queen as a shield when necessary. The key idea behind my plan is to use the proximity of the black king as a way to limit black's ability to check the white king- in other words, delivering blocks with checks or pins. You should gain tempi to move the pawn slowly forward by doing this. So, I would start with 1.Qe5 here and work from there. If you don't do this, and try to move the pawn forward or the king forward first, the black queen will harass the white king endlessly preventing him from ever crossing the 4th rank successfully- getting in 1.Qe5 is going to be critical.