Adding tracks to collection Cross 3.2.0

Hi Guys,
Before I overwrite something... All my collection is now fine and running. So, say I get 30 tracks to add all in different folders under a main root folder on my PC - do I then drag that root folder (with many subfolders) onto the collection node and any tracks not in the collection will then be picked up when scanned & then added, it wont affect any tracks in the collection already will it?
Cheers John
Before I overwrite something... All my collection is now fine and running. So, say I get 30 tracks to add all in different folders under a main root folder on my PC - do I then drag that root folder (with many subfolders) onto the collection node and any tracks not in the collection will then be picked up when scanned & then added, it wont affect any tracks in the collection already will it?
Cheers John