I believe the only way is to insert an image. I'm not sure how they made the image transparent. Perhaps the background of their image is just a screenshot of blank Mathcad sheet.
I have been researching , and got this:
Follow the steps in the manual , but VB generates an error and does not compile
I'm not sure how they made the image transparent. Perhaps the background of their image is just a screenshot of blank Mathcad sheet.
If you insert an image with a transparent background then you can see the worksheet (and any text, etc) behind transparent parts of that image.
Please note that this is unrelated to inserting an image into Mathcad. This is to link Mathcad and AutoCAD so that they can drive each other. If you want help with this, I would suggest creating a new post. I have never done anything with this integration, so I cannot offer assistance.
As PNG, do not copy-paste, import it. Check the video.
How to transform JPG to PNG with transparent background should be your next question, let me know when you find that answer.