Hi Gilles,
Sorry for the inconvenience.
Please have the requested information as follows.
You can achieve your requirements by using the ToolStripTabItem's 'Position' Property, it will Gets or Sets the zero based index position of tab items. For more information Kindly refer the following incident link and i have included the code snippet as follows.
this.toolStripTabItem5.Position = 2;
http://www.syncfusion.com:91/Support/DirectTrac/incidentview.aspx?incidentID=82029Please let us know if you need further assistance.
We are glad to help you out.
Regards,
Iniyen M.A.