MDX Query Help - Or cube concept?

Hello,

I have a fact table for sales, and a dimension table Client.

I need to create a report where i can show How many clients Joined in per year. Now, i have a the Time dimension and a join_date in Client (which DO NOT link to the Time Dimension).
If i create a cube adding Join_date as a Level of the Client Table, i wouldn't know how to filter that. Do anyone know how can I achieve this result?


Thanks.