The window used to enter the EvaluateStatement command determines whether an equals sign (=) is interpreted as a comparison operator or as an assignment operator.
In the Command window, an equals sign (=) is interpreted as a comparison operator. So, for example, if the values of variables a and b are different, then the command
>Debug.EvaluateStatement(a=b)
will return a value of false.
In the Immediate window, by contrast, an equals sign (=) is interpreted as an assignment operator. So, for example, the command
>Debug.EvaluateStatement(a=b)
will assign to variable a the value of variable b.