Disclosed herein is a method for presenting data flow in legacy programs from one device to another by representing the relation between blocks of code in the legacy program and multiple data variables present in the program. The method and system disclosed herein defines the grammar of the legacy language and builds the relational database of the legacy programs based on the grammar. The method defines the action of a block of code within the legacy programs by identifying data variables and mapping the relation between the actions and the data variables.