export data from my database and create excel file and insert this data to the excel file

Question

hi all,
am working on visual studio 2010 using c#and  i have a form that have combobox that have my courses , now i want to select any course and then click on a button to select a place to save the file i want to create and insert in that excel file student full name , ID ,and  the marks of these students
how is that , plz i need  ready code for this solution
thx all.