gassis:
You should be able to use a Slab. In the Slab dialog box, under Floor Plan and Section > Floor Plan Display > Show on Stories will determine on which stories the slab will be shown. Then under Project Preferences > Construction Elements you can control the line type for this element when it is above or below the element's home story. These settings do not use the Floor Plan Cut Plane.
You should add a Signature to your Profile (click the Profile button near the top of this page) with your ArchiCAD version and operating system (see mine for an example) for more accurate help in this forum.
David