OK. I found some more information, but still can't get it to work.
This link has instructions for disabling and enabling add-ins.
https://support.office.com/en-ie/ar...fa9-9b88-403625a0b460?ui=en-US&rs=en-IE&ad=IE
That part works. If I disable my add-in, none of the functions inside work. If I re-enable it, they work again.
I created a code module (Module1) and copied several UDFs from my add-in to that module. I had to do that while the add-in was enabled or it would disappear from the IDE.
When I tried to save the workbook, got an error message saying that I needed to save it as a macro-enabled workbook. When I gave the wrong reply, it deleted all the code form Module1. So I had to repeat the process. (Grrrr...)
I then disabled my add-in, but all of the UDF calls got a
#NAME error. When I looked at one of the cells, the simple call (=xyz(A1, B2)) was had the full path to the add-id prefixed (something like 'c:\aaa\bbb\...\zzz'!zyx(A1,B2)). So I had to edit each cell and remove the path.
I would like to know how to avoid that step.
But after all that, I cannot get the UDFs in the code module to execute.
What am I doing wrong?