Looking to pass values from Execution Plan set up

Not sure if it is possible, I don't use the Execution Plan. May I suggest a different approach.

Let's assume you are reading from excel sheet all the user names.
On the project properties you create a variable type "data table" to load excel sheet. 
On the login script properties you create a UserName parameter.
On a top controller script you create a data loop to go thru all the sheet values, and call the login script pass to it each value.