My workaround was this
I created an expression filed in the query
Sex: IIf(Left([Membri_Partid]![CNP],1) Mod 2=0,2,1)
and filtered it with
Like IIf([Forms]![Cautare_Membru_Frm].[Gender]=0,"*",[Forms]![Cautare_Membru_Frm].[Gender])
Nice and smooth, without those tons of IIf's I am trying now...