DEIU: How to concatenate xlat fields by using its xlatlongname rather than fieldvalue's field

Hello,

In a Map Definition setup, for a line of mapping I use a concatenation of 2 translate fields together.

But in this case I would like the process to concatenate the fields by taking its xlatlongname's field rather than Fieldvalue's field.

To do so I set the mapping by using both Concatenate and XLAT transform type options together.

In the setup we can choose an XLAT transform type but when we associate it with the Concatenate transform type, the process reconizes the Concatenate transform type only and ignore the XLAT option.

How do I do to ask the process to take into account both options please?