A system and method for referencing object instances of an application program, and invoking methods on those object instances from within a recognition grammar. A mapping is maintained between at least one string formed using characters in the character set of the recognition grammar and instances of objects in the application program. During operation of the disclosed system, when either the application program or script within a recognition grammar creates an application object instance, a reference to the object instance is added to the mapping table, together with an associated unique string. The unique string may then be used within scripting language in tags of the rule grammar, in order to refer to the object instance that has been "registered" by the application program in this way. A tags parser program may be used to interpret such object instance names while interpreting the scripting language contained in tags included in a recognition result object. The tags parser program calls the methods on such object instances directly, eliminating the need for logic in the application program to make such calls in response to the result tag information.