Update Hierarchy from file flat

Hi,

We have transferred the hierarchy of infoobjet 0IM_REPOBJ  from OLPT, and a new hierarchy is created in SAP BW.

Now we want to add new characteristic (node)  to this hierarchy, from upload file flat.

I have followed all steps of documentation from sdn but I can't do it.

After that, I think that from uploading file flat, only is possible created a new hierarchy or update a hierarchy created before for this way.

It's correct or exist any way for update by uploading file flat, of a hierarchy downloaded from OLPT?,

Best Regard,

Mario.