withholding invoice item line account from original invoice distribution

Summary:

This is what is happening-

Stage1:

Invoice Item line Distribution segment2-1001

Invoice AWT line Distribution Segment2 - 9999 (from setup)

Stage2:

After accounting-

Invoice Item line Distribution segment2-1001

Invoice AWT line Distribution Segment2 - 1001(from SLAM)

Stage3:

WHT Invoice created-

WHT Item Line - Segment2 - 9999 (from setup)

Stage4:

WHT Invoice Accounting-

WHT Item Line - Segment2 - 9999 (from setup)

What is expected -

Stage1 & 2 fine

but in stage3:

WHT Invoice created-

WHT Item Line - Segment2 - 9999 (from original invoice AWT accounted/original Item line)

Can someone please let me know how to achieve this through SLAM or any functional setup?