Thank you very much for your response. I wanted to display the bookmark title that's why, I was using PDXlateToHostEX()
As you told, i can set the bookmark title with special characters using
ASText asText = ASTextNew();
PDBookmarkGetTitleASText(pdNewBm, asText);
PDBookmarkSetTitleASText(pdNewBm,asText);
But sometimes, I want to modify the title or i want to get the bookmark by title using PDBookmarkGetByTitle().