You can create a combination chart that contains a mixture of columns, lines, and areas. Note that the combined chart types must have compatible stacking (that is, you cannot combine stacked columns with lines; you can only combine stacked columns with stacked lines).
Both charts and series have a Type property. Setting the Type property for the WCChart object changes the chart type for every series. Setting the Type property for the WCSeries object changes only that series if the new series type must be compatible with the rest of the chart. If the new series type is not compatible, the entire chart will change type to accommodate the changed series. This means that if you change one series to a line series on a clustered column chart, you will create a combination column-line chart. On the other hand, if you attempt to change a series on a clustered column chart to a pie series, the entire chart will become a pie chart.