Changing chart axis title on inactive sheet

I have a workbook with two worksheets, one with data, the other with charts of those data. I want to change what is plotted on the charts using a simple dropdown box to select category and values and ideally I would like the chart axes to reflect these changes. All the code I have tried uses the ActiveSheet method like below and this works fine if I am on the actual chart sheet.

ActiveSheet.ChartObjects("Chart 30").Activate
'ActiveChart.Axes(xlCategory).Select
With ActiveChart.Axes(xlCategory)
.AxisTitle.Text = "blah-de-blah link to cell, etc"
End With

BUT, I also want to do this from the data sheet and it doesn't work (runtime error). Is there any way in VBA to access the Chart properties on an INACTIVE worksheet or am I trying to do the impossible?