Sorry, still don't understand.
The number of pins is taken from the schematic symbol.
Ok, by whom? Do I have to do some special action to "take the number of pins from the schematic symbol"?
"Filter by pin count" is only available in the cvpcb dialog I think.
Ok, we progress. Not available in the cbpcb dialog, thant's one thing. Now, is the "filter by count" available from somewhere else (i.e. is there a better place than from schematic -> edit to asssign a footprint, and which allows to select by pin number)?