Append structure extraction

hi gurus...

I want to make a enhance of 0PU_IS_PS_2 datasource, so I want this to provide me the field HSLVT from FMIT table.

So I wonder if is valid to append an amount field (I know that it is possible with characteristic values) to a structure extraction and then map this new amount field to a ratio on the infocube.

regards

joker