Hi @Anonymous,
I am sorry to let you know that, ArtCAM Express doesn't have capability to transfer/export the Relief/model/Clipart Relief (even with any additional Module/s).
ArtCAM Express was part of the ArtCAM product range unit it last release 2015 R2, but is not a part of the present ArtCAM 2017 product range. ArtCAM Express and its associated modules have been discontinued. For various FAQ regarding older ArtCAM Express, please have a look at this click here article in the Autodesk Knowledge Network.
The present ArtCAM release is ArtCAM 2017 and it is available in three different variants: Free, Standard and Premium. Please download the PDF document available at the end of the above mentioned FAO article which lists the features comparison between the above mentioned ArtCAM 2017 variants.
As rightly mentioned by @ahreum.ryu there is a tool called ‘Create mesh’ which can be used to export the Relief as an stl format, but this tool is only available in ArtCAM Standard and Premium.
ArtCAM Standard 2017 and ArtCAM Premium 2017 is available to purchase on a monthly or annual subscription basis from the Autodesk Store. Following are the Autodesk Store links,
For ArtCAM Standard 2017 : Click here
For ArtCAM Premium 2017 : Click here
I am sorry I couldn't be much help here, but hope this answers your question. Please let us know if you require more help; we will be more than happy to continue assisting you.
Thanks and regards,