I assume you want to see the workflow library so you can use the workflows.
Although you could probably reference the library you won't be able to run
the workflows it contains. These workflows require that Windows Workflow
Foundations (.net 3.0 framework) be installed on the server. That won't be
on your SharePoint 2003 server. Installing .NET 3.0 on the SharePoint 2003
box may not even be an option if you are running SharePoint Portal Server
since it is incompatible with .NET 2.0 or 3.0. Finally, it won't work
because all the builtin workflows include a WSS v3 specific activity which
if I remember correctly is called OnTaskCreated. This won't be available in
SharePoint 2003.

So the short answer is no, you can't make use of SharePoint 2007 workflow on
a SharePoint 2003 server.