Can I close Excel using a macro?

[LAM]

I recently made a switchboard in Access.
In the switchboard I used a macro to open a file in Excel.
I used the RunApp macro with the command line: excel.exe "c:\my files\my
file.xls"
It works great to open it....
My question now is: Can I use a macro to close it as well?
I am very new at this and did not want to get into a lot of coding and such
to do this operation.

Thanks for any help you can give me,