Hi Christian,
Sorry for the delay in getting back to you.
You can add GridControl to ToolStripEx of RibbonControlAdv using ToolStripControlHost class.
The following code snippet illustrates this.
[C#]
// Adding GridControl to ToolStripEx2
ToolStripControlHost host = new ToolStripControlHost(this.gridControl1);
this.toolStripEx2.Items.Add(host);
Please refer the sample below and let me know if this helps.
http://websamples.syncfusion.com/samples/Tools.Windows/F63572_new/main.htmThanks for your patience.
Regards,
Jaya