So I couldn't figure out io.dll, but I did manage to get an AutoIt script to control the data pins using inpout32.dll. The command looks like this.
DllCall( "inpout32.dll", "int", "Out32", "int", 0x378, "int", 1 )
The last value (1) controls what is written to the port.
Next I need to figure out how to have RR launch a program when I switch to or leave the radio window, and then I'll take a look at the dreaded flipping of bits during powerup. Anyone want to offer any tips?