Do not include the length, or format, of the clue in the clue editor, but in the Word Format input line. By default, this is just the number of letters in the word, which is entered automatically. However, if the 'word' is hyphenated, or more than one word, you can enter the format here. Just type the number of letters in each word, or hyphenated half word, and a comma to indicate a new word or a hyphen to indicate a hyphen. The format is then automatically included in brackets at the end of the clue you print it. The word is also correctly formatted in the dialog box and when you print the answers.
You can also change the format simply by correcting the punctuation in the word given at the top of the clue editor window. You can also change the capitalization, and use the right-click menu to change to lower case, upper case or initial caps.
For example if the word is displayed as “ontopoftheworld” (On top of the world), then type '2,3,2,3,5' in the format line. If the clue is linked then enter the format for the linked solution.
You can select to either add the format to the end of the clue or not by selecting the Print solution lengths in the clue properties dialog box. Most British cryptics do have the format, most American non-cryptics do not.