ReadingOrder Property [Excel 2003 VBA Language Reference]
Returns or sets the reading order for the specified object. Can be one of the following constants: xlRTL (right-to-left), xlLTR (left-to-right), or xlContext. Read/write Long.
Some of these constants may not be available to you, depending on the language support (U.S. English, for example) that you've selected or installed.
This example sets the reading order to right-to-left for the chart title of Chart1.
Charts("Chart1").ChartTitle.ReadingOrder = xlRTL