@Yachti Sure, you can access expression outside the iteration. For example see the following template and code:
List<string> list = new List<string>() { "First", "Second", "Third" };
Document doc = new Document(@"C:\Temp\in.docx");
ReportingEngine engine = new ReportingEngine();
engine.BuildReport(doc, new object[] { 100, list }, new string[] { "Points", "List" });
doc.Save(@"C:\Temp\out.docx");