Add image button to column without text data in it.

Hi,
Wow your grid it's so cool and powerfull, but....
After a couple days of reading and searching topic in your forum and testing some of the hint in it, it seem there's no clear example or way to do it.

I know it possible, but cannot figure it out how to do it.

I need to add 2 images button in 2 different column (Edit and Del) for each row of data.
I want those button to trigger 2 different external javascript function with a value attribute passing from a hidden column.

Thanks for your help