IN the apps folder, there is a file called SOURCES. Open it with a text editor and somewhere in the beginning add "iplay.c" on a new line
for example:
rockboy.c
solitaire.c
xobox.c
would become:
rockboy.c
iplay.c
solitaire.c
xobox.c
Your file is going to be bigger than that, though. and in a different order