When doing the column mapping, we have to select the Format with microflow as Yes and map the microflow which consist of converting the String type to Enum which is written in modeler.
In the microflow we have to take parameter which accepts a String type. Now we can create a variable of type enum and based on the parameter we have to do conditional handling and assign the enumerator value to the variable and finally we have to return this variable at the end event.
At times even though we have created a microflow, this won't get reflected in the application when we try to do the mapping. So we need to open the model reflection page and check the module where the microflow is present and click to refresh. In this way we can view the microflows.
Are you able to trigger a microflow during the import? I do not the DB replication module well but for instance the Excel importer you can call a microflow where you can do conversion stuff. In the microflow you need to map the strings to the right enum.