BPC 10 NW: MBR_SEQ in BPC 10

Hi Gurus

I need some help in using MBR_SEQ in one of my reports in BPC 10. In 7.5 we had this property by which we could define the sorting sequence in the report but since it is not there and we need to sort account members in one particular sequence, i had used a custom property and defined sorting as per that property in EPM report editor which works fine. Now the issue is, user is not able to drill-down on account member nodes and it says that drill down is not possible when sorting by property is used. Do you have any idea how we can control the sequence of members (like MBR_SEQ) without using property.

Thanks

-SM