Hi,
From a word macro, how can I switch to an excel workbook that is already open to run an excel macro within it?

Any examples online of working with excel through word show the need to open a new instance of excel and open the file in order to have access to it. I would like to avoid this as it takes a long time to open the workbook. And if this cannot be answered, then how could I switch to a specific document in word that is currently open through word vba?