Phil,
I may not be understanding your question but would a macro like the example
below do? It extracts the text in the first series data label to an variable
of the integer type and then references that variable in a formula in cell
A1. In this example, the formula would look like "= 6 + your label value +
4". Click on your chart to activate it and then run the macro. If it works
for you, it would need to be modified to your specs:
Sub DataLabelTextToFormula()
Dim Cht As Chart
Dim Val As Integer
Set Cht = ActiveChart
Cht.SeriesCollection(1).ApplyDataLabels Type:=xlDataLabelsShowValue
Val = Cht.SeriesCollection(1).Points(1).DataLabel.Text
Worksheets("Sheet1").Range("A1").Formula = "=6+" & Val & "+4"
End Sub
Other than that, you can always direct reference the data source in your
formula as it is the same source for the data label.