Hi,
If its different cube then you can directly add required info object to cube. Because for your needs you may create new cube.
about mapping, that will be taken care by BPC retraction method - am not much familair.
As bw consultant you can add or create a cube with required fields.
in your case remodeling is not needed. if cube have no data then directly you can required info object to cube under dimension.
About mapping: its depend on method, how you retract data from BPC.
That you can check at BPC forum.
Thanks