RE: Calls an Excel Template that generates a list of the related applicable contact records .For the time being just use a place holder excel template
An Excel Template can only include the data from the records in the grid or subgrid that it is run from. A simple solution could be to create a subgrid that contains the related applicable contact records and, if necessary, fields from the parent entity, and run the template from that.
If that's not sufficient, it may be better to create a Reporting Services report, which can be exported to Excel - this gives more flexibility in the data you can include