Hi Michael,
Yes, you can make use of custom show to achieve this.
First, click Slide Show > Custom Shows.
Create a new custom show and add the animated slide into the custom show.
Close custom show.
Click Slide Show > Slide Transition.
Under Advance Slide, put a checkmark to "Automatically After".
Click Slide Show > Set Up Show.
Under Show options, put a checkmark to "Loop continuously until 'Esc'".
Click Ok.
Right click on the thumbnail of the animated slide, select Hide Slide.

Now, add a dummy (blank) slide just before the animated slide.
Create an action button on the dummy slide and have the action button
hyperlinks to the Custom Show. This will allow you to enter the custom show
once you click on the action button.
Put a checkmark to "Show and return" if you want to return to the dummy
slide.

When viewing the presentation, clicking the action button on the dummy slide
will bring you to the animated slide. Once you are ready to start the
presentation, press Esc key to go back to the dummy slide. Then advance to
the rest of the presentation by pressing Enter key.