Pb. to texture in game but not in P3D

[PicVert]

I have made a Fas90GR (assaultRiffle with GrenadeLuncher),

1 -  When I open my model to OFP it will a texture that I have never added to my p3d ?? I look in my cpp **not in**
in all objects in p3d **not in** ?? HELP HELP  

2 - Where I can find a defined GrenadeLuncher *.cpp file,
I don't know difine a working GrenadeLuncher  :'(

THX