create NSIS installer with 7z or zip?

[pizzaM4N]

Hello,
I want to create an installer for wiles with a total size of 4GB. I am a novice at working with NSIS.
There are 4 zip or 7z files in a folder with the setup(wich I try to create now). Each one is about 1GB big. The setup should unpack this archives to the installation folder (for example c:/programfiles/MyApp) the user choses when he runs the setup.


my code:

SetCompress force
SetCompressor lzma
Name "MyApp"
OutFile "MyApp.exe"
InstallDir "$PROGRAMFILES\MyApp"
Page directory
Page instfiles
Section "MyApp"
SetOutPath $INSTDIR

SectionEnd

Where do I have to edit which command that MyApp.exe unpacks the 4 1GB files to the chosen install folder?

regards pizzaM4N