Double Handling within working code Write to access and fire access macro

I don't see why you shouldn't be able to execute those queries just are you are executing these queries.

.Execute "Delete * From Dates"
.Execute "INSERT INTO Dates(C1) SELECT * FROM [Excel 12.0;HDR=YES;Database=" & StrWorkbook & "].[Control$ag1:Ag400]"

I might even be tempted to try using the query names rather than the SQL.