Using 32bit application in 64bit

Using 32bit application in 64bit

I am using windows 32 bit VLC media player in 64 bit pc. It is working
fine. but my question is that won't it allocate memory according to 32 bit
structure? That means though i have 64 bit PC, i wouldn't get advantage of
it. Simply 64 bit might have good memory allocation in register than 32
bit. Sorry for the simple question but, i am new at Computer Organization
Architecture.
EDITED : my point : using a 32bit VLC player in my 64bit OS (4GB RAM) will
run like a 32bit player running on 32bit system.. so it doesn't make any
sense whether you've 64 bit System or 32 bit system , because it's running
like a simple 32bit system. Thanks in advance.
PS. i want it in technical terms, but i have to answer in NON TECHNICAL
TERMS.(a general user can understand your answer).so try in general
meaning at the end of your answer. thanks for help ..