Unfortunately there is no export from Spark at this time to my knowledge. It is a self-contained solution that is also hosted by Adobe.
You can embed your Spark Page or Video into the HTML page with an <iframe> as shown below where https://spark.adobe.com/page/XXX/embed.html = the URL to your online Spark page or video.
<iframe src="https://spark.adobe.com/page/XXX/embed.html" width="512" height="256" border="0" style="border:0;"></iframe>
In Dreamweaver, go to Insert Menu > HTML > Iframe... manually edit the <iframe> attributes.
Hope that helps.