OLAP -Populating Fact table

I am trying to poupulate a fact table. The fact table contains foreign keys realted to my dimension tables. I want to move the contents of my dimensions table to a temp table which will then allow me to populate the fact table. Unforunately, I cannot use join or union as the dimension tables do not have any relationships.

Can anyone help or have i got the wrong end of the stick ?

Is there any reason that you can't define relationships between the two tables? You mentioned that the "fact table contains foreign keys related to my dimension tables" so you should be able to define the relationship and then use a join.