There's a section under cPanel named "PHP PEAR Packages" where you can install packages located [I'm guessing] on the server for your account.
However, I did a search for "pdo" and the only relevant return for it was "Structures_DataGrid_DataSource_PDO".
Maybe this package could be included in the repository.
NOTE: The link you have in the original post doesn't seem to lead to a valid thread.