The default gallery file (gallery.ccf) which contains the buttons available within prontoedit software can be customized.

The gallery file is actually a CCF in itself. (gallery.ccf)

To customize your own gallery, first load the gallery.ccf file and save it under a new name such as gallery-default.ccf. This will allow you to restore the default file should you ever choose to do so.

Next, reload the gallery.ccf file again, then load the additional CCF file that you wish to add to your gallery, then select merge, then save the gallery.ccf file again. The gallery will now contain the new buttons that you have added which were in the merged file. Save this file again as another file name such as gallery-custom.ccf so it can also be restored if ever needed.

Note that upgrades to prontoedit software will reinstall the DEFAULT gallery and OVERWRITE your custom gallery file. This is the reason for saving your custom gallery file under another name each time you add to it so you can always restore it after an update software version has been installed. After installing a new version of prontoedit software, just load your gallery-custom.ccf, then save it as gallery.ccf to overwrite the default file that the update installed.