Applications cannot call the AssignTo method. To assign the properties of a THTMLTableColumn object to another object, use the Assign method of the destination object.  

When the Assign method of another object specifies a THTMLTableColumn object as the source of the assignment, the AssignTo method of the THTMLTableColumn object is called. AssignTo checks whether the Dest parameter is another THTMLTableColumn object, and if so, copies the values of all properties except Custom and DisplayName. If Dest is any other class of object, the inherited method is called. 

Custom 

Assign 

AssignTo