Drawing multiple TCanvas into Single canvas

[hym]

Hello All,
I have, for e.g. 2 canvases, cn1 and cn2, stored in different ROOT files i.e., cn1.root and cn2.root. Both canvases have multiple elements, e.g. TGraphErrors, TLegend, TPaveText, etc. I want to take these full canvases and plot them side-by-side on a new canvas.
It could be easy but did never try. Could you please provide a simple macro to do that?
Thanks a lot!

[couet]

{
   TFile *f = new TFile("cn1.root");
   TCanvas *c= (TCanvas *)f->Get("cn1");
   TList *l=c->GetListOfPrimitives();
   TH2D *h = (TH2D*)l->FindObject("histo");
   TCanvas c2;
   h->Draw("col")
}