Here is a solution that involves an MSI custom action. I have written in using C#, but any other language capable of calling a DLL can be user. Here is a tutorial link for C#: Walkthrough: Creating a Custom Action

using System;
using System.Collections;
using System.ComponentModel;
using System.Configuration.Install;
using System.IO;
using System.Runtime.InteropServices;

namespace InstallType1Font
{
    [RunInstaller(true)]
    public partial class Installer1 : Installer
    {
        public Installer1()
        {
            InitializeComponent();
        }

        [System.Security.Permissions.SecurityPermission(System.Security.Permissions.SecurityAction.Demand)]
        public override void Install(IDictionary stateSaver)
        {
            base.Install(stateSaver);
        }

        [System.Security.Permissions.SecurityPermission(System.Security.Permissions.SecurityAction.Demand)]
        public override void Commit(IDictionary savedState)
        {
            base.Commit(savedState);

            // here, you'll have to determine the proper path
            string path = @"c:\Windows\Fonts\MyFont.pfm";
            if (File.Exists(path))
            {
                InstallFontFile(IntPtr.Zero, path, 0);
            }
        }

        [DllImport("fontext.dll", CharSet = CharSet.Auto)]
        private static extern void InstallFontFile(IntPtr hwnd, string filePath, int flags);

        [System.Security.Permissions.SecurityPermission(System.Security.Permissions.SecurityAction.Demand)]
        public override void Rollback(IDictionary savedState)
        {
            base.Rollback(savedState);
        }

        [System.Security.Permissions.SecurityPermission(System.Security.Permissions.SecurityAction.Demand)]
        public override void Uninstall(IDictionary savedState)
        {
            base.Uninstall(savedState);
        }
    }
}

As far as I know, InstallFontFile is undocumented, but allows to install the font permanently. Use this at your own risk.

Note: you still need to modify the .MSI to ensure the Fonts file have a FontTitle as described in the link you gave.