header condition in vf03

Hi Experts,

I know the # of VBELN of VF03 (VBRK), now, I need to pull the data of,

1- Header Level tax - Condition Value

Normally, I know the procedure is,

(The relationship is )

KONV-KNUMV = VBRK-KNUMV

For all the columns the field KONV-KWERT can be used

But, its ITEM level, where as I am looking for Header Level?

So, Where Can I get the VBRK-KNUMV Header level,

Tax Condition Value data?

Thank you,