I have a excel question to request for your help.

ColumnA Column B Column C Column D
1001 9001 2 9801, 9802
1002 9002 1 9803
.....

according to the below data and put the data in column C (Total count of child) and
Column D ( the name list of child)
in another sheet

Column A Column B
9001 9801
9001 9802
9002 9803
.......