How to retrieve dates that meets a criteria using Query? Exp Build

[Access Rookie]

I have 4 columns/fields of dates in a table: Field A, Field B, Field C &
Field D. These fields can be either filled with a date or left blank. ABCD
are all "Dates".

I want to design a query or report to retrieve dates from Field A. The
criteria is:
Field A must be filled (i.e. there is a date, not a blank); and
when dates in any field of B or C or D are not blank, A must be more recent
than this/those date(s).

How do I write it? I made "A is not null" in the first criteria. And then
I think I should write something like when B or C or D are not blank, A >B or
C or D.....

I would use expression builder. But I am still new. I tried a couple of
them I was not able to make any of them work.

Anyone can give me some suggestions or advice? If I did not make myself
clear, please ask me questions. I really need this to be figured out.

BTW, I am using Access 2010. The expression builder has symbols like "&" and
"AND", what's the difference?

Thanks in advance!!!!!!!!

 

[John W. Vinson]

I have 4 columns/fields of dates in a table: Field A, Field B, Field C &
Field D. These fields can be either filled with a date or left blank. ABCD
are all "Dates".

Was Karl's answer five minutes after your first post not acceptable?