About the Product Substitution, Can I modify the condition records in CRM?

Hi, friends,

I am studying Product substitution those days, and am confused by the relative condition records.

According to CR300_COL92, we cannot modify the those condition records in CRM because they are created in ERP and transferred from ERP.

and we even not allowed to  create a new Determination Procedure in Customizing,

it doesn't make any sense what will we do about this function in CRM.

But according to a materials of CRM4.0,  It seems that we could add some new condition records.

Could some friends offer some information?

thanks

Michael