To write the code to multiply two cells in Excel using VBA, you can use the following code:

This code will multiply the values in cells E4 and F4 and then store the result in cell D4.

Here's a step-by-step guide on how to write this code:

1. Open the Excel workbook where you want to write the code.
2. Press ALT + F11 to open the VBA editor.
3. In the VBA editor, click on Insert Module to create a new module.
4. In the new module, type the following code:
   
   
   Formula:

   Sub MultiplyCells()
    Range("D4").Value = Range("E4").Value * Range("F4").Value
End Sub 

5. Save the module and close the VBA editor.
6. Go back to the Excel workbook and select the cell where you want to run the code (e.g. D4).
7. Press ALT + F8 to open the Macro dialog box.
8. Select the MultiplyCells macro and click on Run.
9. The code will run and the result of the multiplication will be displayed in cell D4.

That's it! You have now written a VBA code to multiply two cells in Excel.