Is a path based on assign?

Hello everyone. I would like to ask if there is any method in the DOS library that could help to understand if a path is starting with an assign.

For example, if I have the following assign
test:

that points to
work:folders

I would like to know if the following is based on an assign
test:folder1/folder2

For that, the NameFromLock() would give me:
work:folders/folder1/folder2

I hope I explain it correctly.