Make it possible to use variables within the data correlation expression

[AlexKaras]

Now when correlating data, it is possible to replace only the whole value of the parameter been correlated with the variable value.

Though it is quite a common case when only partial data replacement is needed.

At the moment, this can be solved with the help of the Set Variable Value operation (often, with the non-trivial expression).

But this workaround:

a) cannot be used in the scenarios that use Call Scenario operation; and

b) clogs up the scenario logic (especially, if more than one variable must be set).

It would be great if it is possible to use variable itself within the data correlation expression. And I beleive that this will not decrease the performance of scenario simulation.

Please see the https://community.smartbear.com/t5/LoadComplete/how-to-pass-variable-directly-in-the-Value-from-the-...  thread as an example that illustrates this request. It would be handy if the approach that the author of the thread tried initially is possible.