The database can't "call" the application. However, in SQL Server 2005 I can think of several ways you could possibly do this, but not in SQL Server 2000.
However, having said that, a database doesn't typically "call" an application. Maybe if you supplied the reasoning behind this necessity we could offer some better solutions.
Scott Klein
Author - Professional SQL Server 2005 XML
http://www.wrox.com/WileyCDA/WroxTit...764597922.html