How can the data flow show the number of values changed by a Derived Column that replaces a given column if a condition is met?

I take a Derived Column Transformation to replace a value as soon as a condition on two other columns is met. How can I see in the data flow how often a value changes by this replacement? Is there a way to show it on the output arrow, or how else can I show the changes inside the data flow? #### PS (not needed for the Q/A) I want to check whether the string input is the same as the lookup output. But sometimes, names (first names and last names) have more than one name in the value, like Taylor-Smith against Smith, or Bob Thomas against Bob. People might marry or might in times fill their two first names so that data might not match over two master data accounts.

(DT_BOOL)(FINDSTRING(name,[Lookup.name],1)) ? 1 : [score_name]

The value of column score_name is replaced by 1 as soon as the name is found inside the Lookup.name, else the value is kept which is between 0 and 1. "Name in Lookup?": You could take any other example like [Replace column values?](https://dba.stackexchange.com/questions/47980/replace-column-values) , the question does not depend on what is done.