Manipulating cells based on duplicate addresses

[bobrob]

Hello,

I have a task to print individual labels for every person listed in a worksheet.
The challenge is, if several individuals reside at the same address and are a family I have to print the last names and first names of all family members on the same label then move to the next address.
Family members are flagged with an "F" or "F1" depending if one or two families live at the same address.

Columns are "last name", "first name", "Address", "Flag".

Data Sample:

Doe John 123 Main Street F
Doe Jane 123 Main Street F
Doe Sam 123 Main Street F
Smith Bob 123 Main Street F1
Smith Mary 456 Next Ave
Brown Joy 123 Main Street F1

Labels should look like:

Doe
John, Jane, Sam
123 Main Street

Smith, Bob
Brown, Joy
123 Main Street

Smith, Mary
456 Next Ave


Any help would be greatly appreciated.