How to Save/Export DataGridview into a single document ?

Question

Every time it  exports the DataGridView as a new word document , i want to keeps on adding the DataGridView into the same Word document.

 

1) if a document does not exist then create a new word document and export the entire DataGridView int it.

 

2) if its exist then export the DataGridView into it

 

please help me to achieve it.

 

Thanks