Customize Total Import Pro CSV - Opencart

General information for the website: We sell Fancy Dress Costumes
Kind of development: Customization of existing website
Description of requirements/features: Hi, basically i have a mega menu installed but our categories in the CSV thats imported are like

Main Category Adult
Sub Category 1920s

But for these sorts i would like:

Main Category Adult
Second Level Decades
Sub Category 1920s etc

So looks like Adult > Decades > 1920s

But with total import pro this extra category isnt possible because Decades isnt for all the Categories.

I could create all the categories manually which isnt a problem, but then when i import with total import pro it will just create the correct categories and leave my categories intact or if i choose to empty store befor import it will use the categories inside the CSV File.

Hope this makes sense if you need anymore information please let me know.
Payment methods: Paypal
Specific technologies required: PHP, MYSQL, OPENCART, Total Import PRO
Similar urls: vps.bluegeeks.co.uk/~stylex
Extra notes: The site doesnt work correct as errors at top but the menu is the kind of thing i want to do i have the MENU but the way its laid out i need it once CSV is imported into those sort of sections