dlg_create_preview_image
int dlg_create_preview_image (sds_hdlg handle, wchar_t *key, void *data);
Create a preview image.
This function associates user-defined data with a dialog box tile.
The handle argument is the name of the dialog box.
The key argument specifies the tile.
The data argument specifies the data via callbacks.
This function returns RTNORM or an error code.