Dynamic JOIN Path

Hi all

I have the following requirement - the universe needs to figure out the Join path based on a response to WebI prompt.

The promot can have two values: As-Is or As-Was

If chosen As-Is the fact table needs to join with the As-Is Start and End date columns from the dimension table.

If chosen As-Was the fact table needs to join with the As-was Start and End date columns from the dimension table.

Is this possible to achieve? May be by writing a case statement along with @prompt in the JOIN statement of the table?

Any ideas or suggestions?

I am in XI 3 environment.

Thanks in advance

Runali