Merge 2 DBs - Dif. Structure ..Need Help

I need to merge two Access DBs but I need to know if it is even possible before I start learning how to do it. It is not easy for me to express the problem but here goes:

DB A:
-Flat Table with numbered indexes
-will use a unique field as my index for the merge
(not the primary key)

DB B:
-The destination
-One to Many relation (table 1 to table 2)
-primary key not numbered field (I think)
-will match primary key to the unique field in DB A
-a few fields from DB A will be appended to table 2

....................DB B
Table1----------------Table2
******---------------************
*-----*-one to many-*-------------*
******---------------*-------------*
-----------------------*-------------*----append----------DB A
-----------------------************...<<<<<<<......***********
--------------------------------------------------------*-----------*
--------------------------------------------------------***********