如何写入动态创建的mdb文件？

I have a web application written in PHP 5.6 and based on CodeIgniter 3 that creates a mdb file for every user that requests it. When a requests is made, a copy of a template mdb file is made into a folder created at runtime.

Here is my problem:

I have to write some data in such file, but I can't open a connection with it. I've tried the following:

odbc_connect("Driver={Microsoft Access Driver (*.mdb)};Dbq=$file", '', '');

and:

$odbc_con = new COM("ADODB.Connection");
$constr = "DRIVER={Microsoft Access Driver (*.mdb)}; DBQ=$file;";
$odbc_con->open($constr);

and also:

new PDO("odbc:DRIVER={Microsoft Access Driver (*.mdb)}; DBQ=$file; Uid=; Pwd=;");

and other similar way found online, but no matter what I try, I always get the error:

[Microsoft][Driver Manager ODBC] Data source name not found and default driver not specified.

I also tried to create a system DSN for mdb files with no database selected, since it is created dynamically, but I keep getting this error.

Am I missing something?

PS: this mdb file is needed for an existing application and I cannot use another format, like for example SQLite without modify that application.