A method and service for enabling a smallest unit of variable data within a data space of a user application to be dynamically updated using an external source. The application GUI is enhanced with a dynamic update utility (DUU) that enables the data unit to be selected and linked to the broker topic. A list of available topics is presented for selection by the user, and the data unit automatically linked to the selected broker topic without requiring user knowledge of the specific linking parameters of the external source. A JMS client application is provided containing a message listener and an application writing protocol. A subscriber is defined for the data unit and subscribes to the particular event broker topic hosted at a JMS provider. When the event broker receives a publication from the data publication source, a copy of the published data is forwarded to the message listener associated with the subscriber, and the message listener provides the data to the application writing protocol. The application writing protocol then automatically overwrites the data unit with the published data.