Host is not allowed to connect

[ashkaan57]

Hi,
I am trying to use MS-Access to connect to a MySQL database on our web site. The web site is hosted off-site by a hosting company. I am using Windows XP.
I created a User Data Source, using MS ODBC with the following info:
Host/Server Name[IP]: mydomain.com
Database Name: db_name
User: mydomain
Password: whatever

(using a PHP file, I can the same user id and password as parameters to mysql_conect(). Of course, I use "localhost" as hostname, whereas in setting up the DSN, I used the domain name.)

In Access, I created a database, selected File/Get External Data/Import and selected the the DSN, but I get:

ODBC -- call failed
[MySQL][ODBC 3.51 Driver] Host ['123.456.789.123'] is not allowed to connect to this MySQL server (#1003)

Using the IP address for the Host Name does not help.
I read in some of the threads that a user needs to be created and GRANTed access. But who would be the user? Why doesn't the userid/password that works through PHP failes to authenticate here?

Thanks.