Softer Piano Sound

I don't mean like using piano, mezzopiano, because those don't solve my issue. They make it quieter, but the beginning of the note still sounds the same. I want it to sound like you are pressing down the una corda pedal on a piano. I can't find anything to make it sound like this. I've been to a few older posts, and they said to choose the soft piano soundfont, but I can't find it.