Please help.

I access my cube via Excel 2007. Curently we provide bands below to slice the cube by
<50%,
>=50 and < 60%
>=60% and <70%
>=70 and <80%
>=80 and <90%
>=90%
The users have a new requirement to slice the cube dynamically that is slice the cube by thier own defined bands. For example parameter, >=55% and < 69% >=70 and < 85%,
>=85% and <90% etc.
How can this be achieved in the CUBE? Is this a calculated Member/set job?

Thanks for your kind response.