Hitendra,
For that exact field in the POC platform, here is what I did to get the same result.
1. Define a nested conditional statement, ensuring that both BC & STAMM are not null
2. Then, create a tagging stage, to create the bcStamm field
3. Then, create the appender, starting w/ the BC field
4. Then create a second appender task, adding in the STAMM field
Note: Ensure that you have the multiple values field enabled & a '-' defined as the separator.
Once in place, the bcStamm field will be created w/ the same formatting & values that the MQE content class parsed the data as.
Thanks!
-Jason