Excel 2007 : How to plot text (non-numerical data) on x-axis of scatterplot

I want my x-axis on the scatter plot to show exactly how it is listed in the data sheet. Currently my x-values are displayed as text representing minutes and seconds (e.g. 14:45, 19:45, ..., 59:45, etc.) in my worksheet and I want my scatterplot to show these as they are seen in the worksheet. However instead of showing the text, it is showing "count" data. Is there any way to plot non-numerical values on the x-axis?