Dynamic Setting for Chart Axis Minimum

I am trying to make a dynamic chart which plots stock prices dynamically. I use Excel 2010 but this also happens in 2007

My problem is:

when my dataset gets past more than 212 points, excel's default min value for the chart goes to 0. If it uses 212 points or below I get no problem. I need to be able to make a 260 dataset into a chart BUT with these restrictions:

1. It must not be VBA since I will be giving this program to people not used to it. the VBA thing will cause problems when deleting the chart. (and the macro notice makes some of my colleagues panic, 3 out of every 5 people in my institution call me on how to fix it)

2. The 260 dataset is non-negotiable (I actually need double, but had that negotiated down)

3. No password protection

Thanks in advance to whoever can help me on this