You can create another executable that can decompress the file. Then, in Application builder, in the "Installer Settings" tab, there is a button that reads "Advanced...". A dialog will open with an option called "Run executable after installation". You can call your decompression executable from there.
Another option is to check
OpenG Builder, which is also an application to deploy LabVIEW software. The zip functions are included, and because is open source, you can modify it so the installer shows the behavior you want.
Regards;
Enrique
www.vartortech.com