I don't want to go back to the store - I saw the soy sauce/anchovy paste combination mentioned on another thread and I am hoping someone can provide the ratio.
I'm not sure of the ratio. Try making it and tasting. I'd suggest a touch of vinegar, water and sugar in the mix. The anchovy paste sounds like a good addition with the soy sauce.
Checking the ingredients label, it reads: water, anchovy extract, salt, sugar. In that order.