How to append data to excel from text boxes ?

I work in windows form c# visual studio 2015

I have Excel file name test in c:/test

I have textbox for username ?

I need when write username ahmed in my windows form in textbox1 and then click button

write in excel sheet

1 ahmed

After that if i write new name as michel

then in excel will be as following

1 ahmed

2 michel

Meaning any new nam written in textbox1 then it will append on excel file with No +1 and name writen in textbox1

this will done when i click to button ?

can any one help me in that