You can calculate the number of files below an archive in the script without relying on file display columns:
var filePath = "C:\\My Test Folder\\Fo.ols.cbz";
var fileCount = FileCountRecursive(filePath);
DOpus.Output("File count = " + fileCount);
function FileCountRecursive(filePath) {
var fileCount = 0;
var folderEnum = DOpus.FSUtil.ReadDir(filePath, "r");
while (!folderEnum.complete) {
var folderItem = folderEnum.Next;
if (!folderItem.is_dir) {
++fileCount;
}
}
return fileCount;
}