How to Pass values from an application to an Excel VSTO Template

Question

I am writing an Excel VSTO Template in c# to display reports for an application. There are multiple reports that share many elements, but want to pass in the type of report as a string, and a reference number as an integer from the application to the template to generate the template. I may also need to pass in a token for a document store website for hyperlinks to those documents to be included in the reports. My question is how to I pass parameters to the excel template file that I can access and set within the vsto template? I am finding lots of information on stating excel from the command line with switches, but not finding anything for defined parameters.

As I am not sure where to get started with this, I have not tried anything yet, other than creating the VSTO template file and addins. I am suspecting I want to read the parameters and set the my internal values in ThisWorbook_Startup()