Sizes of .ICO Files

The Internal Icon Set (Flat) by Chris van Minnen has sizes of 22x22 and 32x32 pixel. I have many Icon Files in .ICO Format which I created . Each of all icons I made has a pixel size of 16x16, 22x22 and 32x32 pixel which are together stored in one .ICO File. But Directory Opus accepts only 16x16 or 32x32 pixel (when checking "Large image size" in Command Editor).
Now the problem I have is, that 16x16 Icons are too small, and 32x32 Icons are too big. Is there another possibility to make Directory Opus recognize the size of 22x22 pixel inside of the .ICO File?

You'd have to convert them into PNGs for that size to be used. 22x22 isn't a standard size for .ico resources.

Using an icon set makes most sense if you have a lot of images you want to use on toolbars:

https://www.gpsoft.com.au/help/opus12/index.html#!Documents/Icon%20Sets/Icon_Sets.htm

Yes, but I haven't got so many icons. Then I'll convert them to PGN to see the result. Thanks!