If MS-Access isn't a requirement for your client, throw it in the trash and
use a real database. But if it is a requirement, refer to its help, in case
of MS-SQL there must be an 'N' before any UTF field of a SQL query. I guess
it has to be something similar to this.

For example:

Wrong: INSERT INTO your_table VALUES (1, 'some farsi  things here...')

Corrent: INSERT INTO your_table VALUES (2, N'some farsi things here...')