Here's a similar solution that converts multiple selected archives:
https://resource.dopus.com/t/how-to-convert-a-zip-to-a-7z-in-a-single-button/42756/2
Not a lot of error checking, either 
Here's a similar solution that converts multiple selected archives:
https://resource.dopus.com/t/how-to-convert-a-zip-to-a-7z-in-a-single-button/42756/2
Not a lot of error checking, either