How to set a variable value on the BPC Data Manager

Hello BPC Experts,

I'm creating a BPC10 NW version demo environment for our prospect customer.

I made a data manager to import BW data into BPC model from BW cube.

I need to import just one month data into BPC from the BW cube that has more than one month data.

When I run the data package manually, I can select a member of the time dimension prompt and I can import specific month data I want.

But, in a case where the program (data manager) runs by JOB monthly,

I can't select a member of the time dimension prompt manually.

So I want to know how to set a variable value to the time dimension prompt from a system date etc. automatically.

Are there any way to set a variable value to the time dimension prompt on the data manager automatically from a system date?

Or, do you have any other solution to import just one month data into BPC from the BW cube that has more than one month data by the data manager running on JOB ?

(without selecting a member of the time dimension prompt of the data package manually)

Thanks in advance,

Keisuke