SQL Injection on SitePoint: SQL Injection Attacks - Are You Safe?
Create an ODBC connection for that Access dB and look at the odbc_ functions in a PHP manual..
The second: How do I connect with PHP to Access dB (Don't ask why...)
for example to open a odbc connection named MYAccessDB you'd do:
There are other options but I'm not too familiar with them. Among them I know that you can create the ADO Com object directly in PHP and then use ADO methods (so if you're familiar with that library it could be a more interesting path the ODBC)
$dbconnection = odbc_connect('MYAccessDB', '', '');