Sort Matirx Column

Hi,

I would like to sort a matrix of a SBO standard-form by a particular column. 

Generally, I found a sort method in the TitleObject in the SDK Help Center but it seems not to work out of a FunctionButton Code.

I did:

oMatrix.Columns.Item("15").TitleObject.Sort(SAPbouiCOM.BoGridSortType.gst_Ascending)

But I get the error message "TitleObject is not a member of SwissAddOnFramework...."

Can somebody help me with how to sort a matrix in a standard-from by a particular column via coresuite customize?

Kind Regards

Christian