Mapping Scripts are used to build mapping logic to derive target members based on multiple source column and IF THEN logic. Mapping scripts are added in the Data Load Mapping screen, and are available for: Between, IN, Like types. They are stored in the TDATAMAP table.
When you use Lifecycle Management to export mapping rules, any related mapping scripts are included.
The import of mapping rules using an Excel template does provides a place to specify a mapping script.