Using Custom Controls
You can use custom controls For example, Visual Basic has a default project file called AUTOLOAD.MAK that includes two custom-control file specificationsGRID.VBX for the grid control , and OLECLIENT.VBX for the OLE control . When Visual Basic starts with no other file specification, the default AUTOLOAD.MAK project is loaded and the icons for the grid and OLE controls appear at the bottom of the Toolbox. You use custom controls the same way as other controls in Visual Basic. in your applications by loading them into the programming environment using the Add File command on the File menu, or by specifying their definition files (files with a .VBX extension) in a project's .MAK file.
Chapter 13, "Using the Grid Control"
Chapter 21, "Object Linking and Embedding (OLE)"