vba vlookup来填充工作表

I have a user form with a combo box and a submit button which enters the selections made by users from the drop down onto a worksheet on the first empty row.The combo box vba works fine. However, for example if the combo box choice is entered in cell C2 (because the first empty row is 2 and C isalways the column where the combo box enters the result) I want in column D to have a vlookup formula in VBA which, based on what it is in column C to autofill AUTOMATICALLY AT THE SAME TIME column D. Like when you drag down a vlookup formula in column D based on the values in column C. I have a user form with a combo box and a submi