[TYPO3-english] TypoScript to get value list from checkbox array

[Sengchheang]

Hi All,

Currently I have a problem with getting value list from checkbox array
because I GP:my_checkbox|###INDEX### can only get one item when form
submitted.

This is my sample checkbox array.
<input type="checkbox" name="my_checkbox[]" value="a"/>
<input type="checkbox" name="my_checkbox[]" value="b"/>
<input type="checkbox" name="my_checkbox[]" value="c"/>
<input type="checkbox" name="my_checkbox[]" value="d"/>

What I need is to get all values of the checkbox to be in comma
separated list (e.q. a,b,c,d,...).
I really really want to get this thing done by TypoScript rather than
userFunc.

Please help me if you have any idea for this with TypoScript.

Thanks,

Sengchheang