These are both Kernel32.dll so have a look in win32.lib using the libmaker to see if they in the WIN32.LIB. If they are then you can prototype them in module(‘winapi’) / End.
But the other thing to consider is what folder traversal method are you going to use? Tree traversal - Wikipedia
What is the problem? Here is an example.
In C6.3 win32.lib contains SHFileOperationA so you don’t need to link custom lib. Just declare the function and SHFILEOPSTRUCT.
This example on GitHub uses all Clarion code (e.g. DIRECTORY) to recursively load files into a Queue and display in a LIST. It does a Rename on files but you could change it to do a DeleteFile() or Remove(). You get a Window with a Progress bar.
You can remove the link and call to SHAutoComplete() which is used to auto fill the folder.
Be careful with SHFileOperationA() as sending it bad parameters may delete the wrong stuff, like your project or everything.