Using for each, in with STL containers with non-const iterators

I want to use the "for each, in" syntax with an STL container, and still
modify the elements of the container while iterating.

I was expecting this to work:

std::vector<int> lst;
lst.push_back(1);
lst.push_back(2);
lst.push_back(3);
for each( int& num in lst ) {
   num++;
}

But it gives the error:
'static_cast' : cannot convert from 'const int' to 'int &'

Why is it using a const iterator when i'm using a reference type? Is there
a way to do this?

This is valid code:
for each( const int& cref in lst ) { /**/ }

....but 'cref' is not an l-value, so you can't modify the elements of the
list while iterating!

And this is valid code:
for each( int clone in lst ) { /**/ }

....but 'clone' is a copy of the element, not the original. Any changes to
'clone' are not reflected in the original 'lst' array elements.

To work around I would write it using traditional syntax:
for( std::vector<int>::iterator i=lst.begin(); i!=lst.end(); ++i ) {
   (*i)++;
}

But how do I use "for each, in" with STL containers (in unmanaged non CLR)
and still modify the elements of the containter?