Hi,
I have experience with data processing, include import and export from/to different formats and purposes.
"This is not a big job" - this is not true !!!!
When you get duplicates and you lost part of you information, or incoming .CSV for some reason start coming in different format, you will understand that this is "big job".
I can tell you more for .CSV importing but this is not your problem - import problems should be resolved by developer who do your project.
Thank you,
Slavi.