With conditional mapping, source members are mapped to script expressions, rather than to hard-coded target members.
Conditional mapping is valid only for rule-based mapping (Between, In, and Like). You activate conditional mapping by placing #Script in the target-member column. This entry triggers execution of the script listed in the Script column.
Because scripts are written in VBScript, all functionality of VBScript is provided and the running instance of the API can be accessed. Conditional mapping, in conjunction with dimension processing order, enables mapping that is based on the results of dimension mappings that were processed previously, prior to the processing of the current mappings.