I've just tried - but I don't think you can define a default value by reference to other fields in the table -
in any event, see my reply to your other posting - you should use forms to enter data, not enter directly into the table.
for access to be anything other than a spreadsheet you need tables to relate to each other. once you have multiple tables, and have set up some relationships, then the value of an entry in a given table is meaningless without reference to contents of an associated table.
eg
in your membership table you have details of "Name", "Adress" , "Phone" . You also need a unique identifier for the table, so you exclude duplicate values. Name may be insufficient - you may have 2 John Smiths for instance, so you should assign an unique Member number to each member.
Now you may have another table for Membership Payments. For each member you store all the payments they make. In this table you need to store the member number from the other table.
Now if you open the Access payments table, the member details you see is just the member no. As the system becomes more complex these "foreign keys" build up, and it is very difficult to follow what is happening from the tables alone. In fact, nobody would try to do that. You process these tables into presentable information through queries and more importantly forms and reports.
I hope this helps. Thers lots of info here in this forum, and its worth getting a good primer from the reading list and getting a good basic understanding of what a (relational) database is all about.