Please be more specific. See Rule #2.

Sreerangan,

do your customer have some type of groupings (by state, by type of customer, etc.) then you can use
Cascading Combo Boxes
to limit the selection.

Alternatively, check out the  
Easy Search Form 2
for inspiration

Have you tryed to start typing what you are looking for this might shorten the list.

Yes. The Easy Search Form videos would be useful for me. But if I had date of birth on my table and made a text box for that too (field named dateofbirth). I am guessing the following would not work for date match because it is in date format:
=Forms!MainMenuF!dateofbirth

Limiting your list by date of birth is a great way to start. I actually have a TechHelp video on this coming out soon. My doctor's office, for example, asks for my DOB first, and then when I give them my name, it's on a short list that they can easily see.

I'll try to show a non-Developer way of doing this first, since you're an Expert user.