Cutting polygon pour around text
@uint128_t is correct. I do this all the time, especially with company logos.

You need an image of what you want to place as a 1-bit monochrome image. Copy it to the clipboard and paste it into the copper layer in Altium. This step usually fails due to image editing programs providing the clipboard data with too much bit resolution. Paste the image into MS Word and then copy and paste it into Altium (sounds wierd but works).

When pasting the image into Altium, you get to re-size it at that point. I advise making a Union of the components of the image too. When you are happy with the image size and placement in the copper layer, copy the image in Altium and paste it into the relevant Soldermask layer to make it gold (if your finish is gold as in the example picture).

Copper pours around your image can then be easily made to keep the standard clearance distance away from your image.