Bug 205782 Excel can't process big data which type is Decimal.
engine/org.eclipse.birt.report.engine.emitter.prototype.excel/src/org/eclipse/birt/report/engine/emitter/excel/ExcelUtil.java
{
	public static String ridQuote( String val )
	{
		if ( val.charAt( 0 ) == '"' && val.charAt( val.length( ) - 1 ) == '"' )
		{
			return val.substring( 1, val.length( ) - 1 );
		}
		return val;
	}
    public static String formatDate( Object date )
	{
       
		SimpleDateFormat dateFormat = new SimpleDateFormat(
				"yyyy-MM-dd'T'HH:mm:ss" );
		return  dateFormat.format( (Date) date );
        
	}
    
    public static String getType(Object val)
    {
    	if ( val instanceof Number )
    	{
    	   return Data.NUMBER;