GRN number range prob

Hi,

We are maintianing the number ranges for material document through an object ZMATBELEG ( in T code snro). In that intervals from 1 to 74 year wise. But when The same was extended for 2008. The GRN numbers are picking up from the object but from OMBT which my client doesnot want.

How can make the system to pck from my object.

Points assured

Thanks

MNM