I was subpeoned to testify as a witness. I am out of state, how do I handle it?

I was a witness to a ual battery. I am being subpeoned from an out of state courthouse in northern indiana. I live in southeast Texas. How can I make sure that my testimony is not thrown out because I can't show for the court session? What do I need to do to take care of this and make sure they guy doesn't walk and go after more underaged girls?