How to create a link from the master report to a subreport at runtime

Hello Jannet,
thank you for your answer, but in my case I have a master->subreport construct, no a master->detail construct. In this case, setting the NavigationUrl to the name of the subreports label name doesnt seem to work.
I modified your demo solution.
reagards,
Michael

Thank you for the clarification, Michael.
First, I see that you place an XRSubreport component to the Detail Report Band. Since the DetailReportBand represents a separate full-funtional report, it is enough to either use the DetailReportBand or the XRSubreport.
Our documentation will help:
How to: Create a Master-Detail Report using Detail Report Bands
How to: Create a Master-Detail Report using Subreports

For now, I've moved the XRSubreport to master's Detail band.

Back to the initial issue: if you want to create a reference to the control that is placed into a separate subreport, it is necessary to create a link between the report bricks manually after your report document is generated.
To do this, get the required bricks from your report document and use the VisualBrick.NavigationPair property to create a link. Please find a sample application at How to create custom Table Of Contents.

Alternatively, handle the PreviewClick event of the master XRLabel and navigate to the child control by using the PrintControl.ShowBrick method (see How to create a cross-reference to navigate from one table to another):

C#
private void LinkToDetailLabel_PreviewClick(object sender, PreviewMouseEventArgs e) {  
        XtraReport report = ((XRControl)sender).RootReport;  
        foreach(Page page in report.Pages) {  
            NestedBrickIterator iterator = new NestedBrickIterator(page.InnerBricks);  
            while(iterator.MoveNext()) {  
                ViewControl previewControl = (ViewControl)e.PreviewControl;  
                Page p = page;  
                ProcessCurrentBrick(iterator, previewControl, p);  
            }  
        }  
    }  
private void ProcessCurrentBrick(NestedBrickIterator iterator, ViewControl previewControl, Page page ) {  
        if(iterator.CurrentBrick is VisualBrick && ((VisualBrick)iterator.CurrentBrick).Text == "DetailReport") {  
            PrintControl printControl = previewControl.Parent as PrintControl;  
            printControl.ShowBrick((VisualBrick)iterator.CurrentBrick, page);  
            return;  
        }  
        if(iterator.CurrentBrick is CompositeBrick) {  
            CompositeBrick cb = iterator.CurrentBrick as CompositeBrick;  
            NestedBrickIterator newIterator = new NestedBrickIterator(cb.InnerBricks);  
            while(newIterator.MoveNext())  
                ProcessCurrentBrick(newIterator, previewControl, page);  
            }  
        return;  
}  

Please find your sample attached and let me know if you have further questions.

Thanks for your update Jannet, unfortunately your approch only works inside the document preview, but not in the export file (e.g. PDF).
If there is no solution which uses the NavigationUrl feature, I will use a transparent label next to my subreport as bookmark target.