It sounds like creative use of the normal radio button question might work for you. Create a normal radio button question and enter the start text and end text for the first and last options respectively. For the blank options, use the HTML non-breaking space character for the text. This can be entered as
in the survey editor.
For reporting purposes, you can use the Alias field to specify meaningful values for the blank options. These values can be shown in reports, but will not appear to survey respondents.
I created an example of this here:
Non-Numbered Semantic
To see the question in the survey editor, log in to our online demo at
Checkbox® 4.3 and search for the survey titled "Non-numbered Semantic"
-N