Set the page number with discontinuous chapter number

Hi,

I want to create a DOCX document with discontinuous chapters and add the chapter number into page number. For example, I want to create a DOCX including chapters 1, 6 and 9 and the page number in each chapter is like 1-1, 6-1 and 9-1. My actions are as follows:

Firstly, I create a document including 3 chapters with section break among them and add page number and set its format as "include chapter number". At this time, My document show three chapters 1, 2 and 3. and the corresponding page number shows like 1-1, 2-1 and 3-1.

Secondly, I change the chapter 2 to chapter 6 by "Right click on the chapter number of 2" -> "Set Numbering Value" -> "Start new list" ->"Set value to: 6". At this time, the chapter number of 2 is changed to 6 and chapter 3 to be chapter 7 automatically, but the corresponding page number is changed to be "1-1" instead of "6-1".

Thirdly, I change the chapter 7 to chapter 9 using the previous steps, the chapter number is changed to be 9, but the corresponding page number is changed to be "1-1" instead of "9-1".

Could anyone help me about it?

Thanks!