vba to calulate matching number between rows

In sheet FAMILY we details of family members with family ID(B), Family member id(C), Title (D), independent family Code (E ) and Number of family member (F)

1) In column B one ID will be same for one family and in column C against one family the family members will be having different member id as per number of family members in column (F ) and independent family code (E ) contains one code for one family.

2) Common id (B) will be any one id from the one family member id (C). For example row number 2 to 5 is one family and family code is 035362 because it belongs to its family member in ROW number 3.
Other example is row number 7 and 8. Both the rows are one family and family code is 008561 because it belongs particular family head.

Task:

In some family the common id of one family might be the id of other family’s head or member’s as given in point no.2. Now in such cases I want to give one unique Joint family code in column G(unique should start from number 1).

Please refer below example and colored marked cells in attachment. Please note that the total number of family members in matching families might be same or might not be same.
Row 2 to 4 is one family with 3 members and its joint family is row number 22 to 24.

Please provide vba assign Joint family code in Column G