You can use this cool functionality if you perform a technical upgrade of your database. This means only using the new runtime (fin.exe and server.exe) on your old business logic.
These are the steps to take after the runtimeupgrade
Implement Office XML in a Technical Upgrade
Codeunit 1
———-
Copy the 3 functions from a 5.0 database
Name ID
LaunchApp 116
SelectStyleSheet 117
ManageStyleSheets 118
Objects
——-
Copy these opbjects from 5.0 to your database
Type ID Name
Form 690 Manage Style Sheets
Form 691 Send-to Programs
Form 692 Import Style Sheet
Form 693 Program Selection
Form 694 Style Sheets
Codeunit 403 Application Launch Management
System Tables
————-
Copy the values from system tables
2000000065 Send-To Program
2000000066 Style Sheet
2000000067 User Default Style Sheet
From a 5.0 database to your database
And your GO
One other advantage of doing a runtime upgrade is having support for Windows Vista.
A good step after this runtime upgrade is to do a functional upgrade to be fully prepared for 5.1.