How to import WBS into P5 from Excel

IS there a way to import just WBS codes into P5?

I am trying to import a huge project with many WBS codes. When I try to import activities, the import kind of lumps all the activities together and ignores the WBS codes I have in my input (import) file.

However, if I go into P5 and MANUALLY create the WBS and re-import, it recognizes the WBS and imports it correctly.

I am trying to avoid Manually creating WBS since I have so many of them, and I think it is a big waste of time to create it manually.

Any pointers?

Thanks much!