create a stored calculation field in the Asset table with calc:
List ( Key1 ; Key2 ; Key3 ; Key4 ; Key5 )
and then relate that field with Software::Key
Thank you that did the trick was a lot more simple then I was expecting
Simple, but in some cases, it may not be your best design option. This may be a case where you need a join table instead of 5 separate fields for you keys.