Write Excel Data to Pre-formatted Excel sheet?

I have a process that generates a report, when I use the Excel Write component, it creates an Excel file, but the output is messy (the text is left-justified in some parts and right-justified in others, the columns aren't expanded properly etc.)

Is there a way to create an Excel document with a pre-formatted table, then write the data there within a Workflow process?  I was told it might be possible be first reading in the existing Excel file, then using an Excel generator, but I'm not sure how this works.

Thanks in advance.