PIX 515

i have my PIX outside net connected to a distribution switch and my PIX internal connected to a PC LAN interface directly.its a Testing Server.My external int is 58.x.x.x and internal int is 192.x.x.x.I created a default.htm in ftproot,i can access it from internal interface of PIX,typing 192.x.x.x,i need that when my external users type the external IP of 58.x.x.x they should resolve to 192.x.x.x and access that default.htm.So how do i go about this config on PIX