Or, asking in other words, how do you derive your unique configurations from the two tables?
I am absolutely unsure what you are trying to achieve. Have you considered using a link table between PRODUCT and OPTIONS table, i.e for a configuration like 100_ADEF, you would built a link table like
LOAD CONFIG,
PRODUCT,
Mid(CONFIG, LEN1+iterno(),1) as OPTION
WHILE iterno()<= LEN2;
LOAD *, Subfield(CONFIG,'_',1) as PRODUCT, Len(Subfield(CONFIG,'_',1))+1 as LEN1, Len(Subfield(CONFIG,'_',2)) as LEN2 INLINE [