Summing parts of 2 histogramms

Hi!

Just a very silly question:
how can i sum parts of 2 1-dim (TH1I) histogramms, which themselves have different axis limits and different number of bins?
Rebin seems to give the right binning, but i dont know how to change the axis ranges.

TAxis *xaxis = hTest->GetXaxis();
xaxis->SetLimits(100,2000);
or
xaxis->SetRange(100,2000);

seems just to shift the histogramm, which is definetly not what i want!
I want to sum just the parts of both histogramms which lie in the range from
xmin = 100
to xmax = 2000!

Thanks for your answer!

Tom

Adding sub-ranges of two histograms is currently not implemented.

Rene