> I have no idea what you are asking.
> 
> > The reason is I have to put those values inside a comment, 
> > so I cannot pass them as variables.
> 
> So your original query about accessing property values from src blocks was 
> not what you wanted?
> 
> Examples of what one is trying to do - even if they do not work exactly as 
> intended - are often more helpful than verbal explanations of what one 
> would like to do.
> 
> Chuck
> 

I'm sorry if my explanation was not clear, but the original example I provided shows exactly what I wanted to do:
* Subtree:PROPERTIES::DUMMY: VALUE:END:#+BEGIN_SRC{{DUMMY}} <- something like this?#+END_SRC
Basically, I want to replace {{DUMMY}} with VALUE, without passing it as a variable. So just like <<noweb>> replacement, but with a property value instead of a code block. I get the feeling that this is not possible, but I wanted to ask just in case. 
Best,Joon