I need to create reports in Excel format, and the easiest way for me to do
that is to have an Excel macro pull the data from the database and use the
data to fill in a pre-formatted sheet that it subsequently saves as a new
workbook. So far so good, I got the macro working and generating the reports.
Now I need to automate those reports in a way that will not require any
human intervention at any stage. I also need to email the reports after Excel
is done generating them.

I'd like to write a VB.NET program that will call the Excel macro (a VBA Sub
in an Excel module), and subsequently email the report.

How can a VB.NET program trigger an Excel VBA macro ?