How to hide points on the chart axis
To hide some points in the Excel 2003 chart axis, do the following:
1. Right-click in the axis and choose Format Axis... in the popup menu:
2. In the Format Axis dialog box, on the Number tab, select Custom category.
3. Change the field Type:
# ###;-# ###;;
The first applies to positive values, the second to negative values, and the third to zero (for more details see Conditional formatting of chart axes).
4. Click the OK button.