int main()
{
... NeroInit stuff...
	NERO_WRITE_CD *write_cd = NULL;
... create your write_cd
	GetIsoTrack( &write_cd->nwcdIsoTrack );
... NeroBurn stuff ...
}

int GetIsoTrack( CNeroIsoTrack** ppIsoTrack)
{
	*ppIsoTrack = NULL;
	NERO_ISO_ITEM* pItem = NULL;
	if( CreateIsoTree( "A:\\Path\\To\\Your\\Files\\*.*", &pItem ) ) {
		cerr << "Error: CreateIsoTree()." << endl;
		return 1;
	}

	DWORD dwFlags = NCITEF_USE_JOLIET | NCITEF_CREATE_ISO_FS | NCITEF_CREATE_UDF_FS |
		NCITEF_DVDVIDEO_REALLOC | NCITEF_DVDVIDEO_CMPT;
	NERO_CITE_ARGS citeArgs;
	memset (&citeArgs, 0, sizeof (citeArgs));
	citeArgs.dwBurnOptions = dwFlags;
	citeArgs.name = "";
	citeArgs.firstRootItem = pItem;
	citeArgs.abstract = "";
	citeArgs.application = "";
	citeArgs.bibliographic = "";
	citeArgs.copyright = "";
	citeArgs.dataPreparer = "";
	citeArgs.publisher = "";
	citeArgs.systemIdentifier = "";
	citeArgs.volumeSet = "";
	// Finally, create the ISO track.
	*ppIsoTrack = NeroCreateIsoTrackEx (NULL, (const char *) &citeArgs, NCITEF_USE_STRUCT);
	if( NULL == *ppIsoTrack ) {
		cerr << "Error: NeroCreateIsoTrackEx()." << endl;
		return 1;
	}
	return 0;
}

// This is from a separate CPP
#include "stdafx.h"

#include < iostream >
#include < io.h >
#include < time.h >

using namespace std;

// Current time is static so we don't have to construct it all the time
static struct tm *date = NULL;

int CreateIsoTree( const string &Dir, NERO_ISO_ITEM **Root_item )
{
	intptr_t file_handle;
	struct _finddata_t rec;
	string path = Dir.substr( 0, Dir.rfind( "\\" ) +1 );
	string s;
	NERO_ISO_ITEM *new_item = NULL;

	if( NULL == date ) {
		time_t t;
		time( &t );
		date = localtime( &t );
	}
	
	file_handle = _findfirst( Dir.c_str(), &rec );
	if( -1 == file_handle )
		return 1;          // invalid path
	do {
		s = rec.name;
		if( ( "." == s ) || ( ".." == s ) )
			continue;
		s = path + s;

		new_item = NeroCreateIsoItem();
		if( NULL == new_item )
			return 2;
		new_item->entryTime = *date;
		strcpy( new_item->fileName, rec.name );
		strcpy( new_item->sourceFilePath, s.c_str() );
		if( NULL != *Root_item ) 
			new_item->nextItem = *Root_item; // easier and faster to add to the beginning
		*Root_item = new_item;
		
		if( rec.attrib & _A_SUBDIR ) {
			// Directory
			new_item->isDirectory = 1;
			CreateIsoTree( s + "\\*.*", &new_item->subDirFirstItem );
		}
	} while( 0 == _findnext( file_handle, &rec ) );
	_findclose( file_handle );
	return 0;
}