title: How to add/Delete lines of code to a "ThisWorkbook" of excel file using vb.net?
body: <p>As per my application I want to write some Lines code in "ThisWorkbook" of Excel file using vb.net,before that we need to check the file for existance of code.</p>
  
  <p>Please let me know any code or links for reference..</p>
  
  <p>thank you...</p>