Trying to create a Modeless Dialog Box in WinAPI but without using a predefined Resource file.

How would I go about doing that with CreateDialog()?

Documentation states for the second parameter:

lpName
Type: LPCTSTR
The dialog box template. This parameter is either the pointer to a null-terminated character string that specifies the name of the dialog box template or an integer value that specifies the resource identifier of the dialog box template.
Could someone provide an example that uses a "null-terminated character string"?

How do I define the characteristics of the Dialog Box if I'm not using a Resource.h or .rc template?

Have tried researching examples online but they all seem to use Resource files.

Also, how do I determine the correct value to place in the first parameter (HINSTANCE)?