Data Copy from one member to another

Hi,

I need to copy all data from one member to another member from the same dimension.

To be more specific, I have a category dimension with these members:

Category
->Budget
->Forecast

And I want to start my Forecast with the Budget data from last year * 1.05. Because I will change the values from forecast I can't just put a formula (forecast = budget *1.05, if I do that the cube will always show the formula values and not some new values that I want to enter).

Is there a easy way to do that? Any tip will be great.

Thanks,
Handerson