Hi Mollie
Attach and Link are features of iClone 8. In Character Creator 4 clothing and hair is automatically attached (parented) when applied from your content library. The same applies when creating custom accessories (clothing, hair, shoes, props) using the Create > Accessory option. Custom clothing and hair created this way will be automatically parented when applied.
With this in mind you should be able to export from CC4 using the Unity pre-set option and not encounter any issues.
If you would like to know how Attach and Link work you can find out more
HERE.
And for Unity specific tutorials please see
HERE. These should help you get your characters into Unity and functioning correctly.
Peter
Forum Administrator
www.reallusion.com