So you would have to write any errors to a log file using the PowerShell script that you use to read the CSV as an input file. If you use the Start-Transcript function you should capture any errors or alternatively you could use an array to capture any errors
and then write the contents of the array to a log file. Her's an example:
$transcriptname = "EnableEVUsers" + `
(Get-Date -format s).Replace(":","-") +".txt"
Start-Transcript $transcriptname
