MainOOConnect

//Listing 0b Again our starting main Code
int main( ) {
//retrieve an instance of the remote service manager
    Reference< XMultiServiceFactory > rOfficeServiceManager;
    rOfficeServiceManager = ooConnect();
    if( rOfficeServiceManager.is() ){
        printf( "Connected sucessfully to the office\n" );
    }

//get the desktop service using createInstance returns an XInterface type
    Reference< XInterface  > Desktop = rOfficeServiceManager->createInstance(
    OUString::createFromAscii( "com.sun.star.frame.Desktop" ));

//query for the XComponentLoader interface
    Reference< XComponentLoader > rComponentLoader (Desktop, UNO_QUERY);
    if( rComponentLoader.is() ){
        	printf( "XComponentloader successfully instanciated\n" );
    	}

//get an instance of the spreadsheet
    Reference< XComponent > xcomponent = rComponentLoader->loadComponentFromURL(
	OUString::createFromAscii("private:factory/scalc"),
        OUString::createFromAscii("_blank"),
        0,
        Sequence < ::com::sun::star::beans::PropertyValue >());
// add code here
    return 0;
}

This code is called a bootstrap and uses :

• com.sun.star.lang.XMultiServiceFactory, com.sun.star.uno.XInterface and com.sun.star.frame.XComponentLoader interfaces
• com.sun.star.frame.Desktop service.

Remember each time you query for an interface you have to add code lines (if they don't exist) in the source code and a line in the makefile. I will generally add comments to prevent omissions. You can find more explanations here (if you are not a beginner).