[SmartForm] Merging cells of different rows

Hello,

I am new to SmartForms and I have a question for the people that know (a little bit) more about it:

I know it is possible to simulate merging of cells of different columns by using another row type, but I can't find anything to do the same with cells in different rows! It seems impossible to me but I just want to be sure!

Thanks in advance!

With kind regards