How can I give Excel 2002 the command to print a worksheet for me from C# ?

I have this code:

Excel.ApplicationClass app = new Excel.ApplicationClass();
Excel.Workbook sht;

sht = app.Workbooks._Open(filename,0,true,5,"","",true,Excel.XlPlatform.xlWindows,"\t",false,false,0,true);
sht._PrintOut(1,1,1,false,true,false,false);

I hope this is right, but if someone can help me it would really help me out !