Save the template that contains the Autotext and copy it to the new computer. Then use Organizer (Tools>Macro>Macros..., Organizer... button) to copy from the old template to any new template that needs the autotext.
If you want them all to be always available, copy them to the new Normal.dot.
If they are all in the old Normal template, you could consider importing all of the customisation in the template (includes macros, styles and toolbars) by simply replacing the new Normal template with the old one.