WC_SPLITPANE programming reference

The splitpane control fully respects the PM control standards.
Both its look and its behaviour can be easily changed via presentation parameters or the control specific styles, while the SPLITCTLDATA data structure allows full control on its initial values on window creation or in dialog scripts.

Besides that, a rich set of function-like macros provides an easy way to modify or retrieve the state of the control and its components after the window creation.