Adding Z-Field to CR General data section

Hello Gurus,

Our requirement is to add one custom field in Change Request - General data (Along with CR Description, due date etc...).

My initial investigation says that i need to add custom field to structure: BSS_CRIL_ROOT_ATTRIBUTES.  Can any one please confrim is it the only place or do i need add the custom field(Attrinbute) to any other Entity  ? 

All i want to use this field to route the workflow process. I do not need this attribute at ECC layer.

Any one had got the similar requirment earlier? Any documents on this?

Thanks in advance.