Need to capture Time to first byte for scripts running in WinInet mode

Need to capture Time to first byte for scripts running in WinInet mode

There are some files to download. Need to capture "time to Start download" and "total download time".

Total download time, i will get from transaction response time, please help how to find 'time to start download' or 'time to first buffer/byte'.

Scripts are running in Wininet mode, Socket level not working for replaying scripts, hence Web page diagnostics data not available.

 

Please advise.