Yes. Just create the question wording for the custom item as you would for any other item (i.e., using < > to indicate variables). Then in your html file, just place "ml.wording" wherever you want it...

[edited from support email]

Is there any way to add information to this from a responses.xls file
to display on the screen?

Here is a custom item for v2006 that requires a password to continue. It's a simple html file that can be referenced as a "custom" item type in any questionnaire. The html can be modifed in any way...