The underlying API behind "actxserver" is Microsoft's COM interface. MATLAB simply leverages the COM interface to make calls using Microsoft's APIs. For questions on using the COM interface and syntax please consult Microsoft Documentation and Microsoft Technical Support if necessary.
For copying sheets, please refer to the following documentation page.
Using this, you can use the Example script attached. The crux of the example is at:
a = e.ActiveSheet;
e.ActiveSheet.Name = "gsData_01";
The first step is to get the active sheet, which in this case is the sheet to be copied.
Next we use the "invoke" function to call the sheet copy method documented in the link above. We are using the optional argument "After" (as noted in the documentation) with the active sheet again in order to place the new sheet after the copied sheet.
Finally, the newly copied sheet is set as the active sheet and thus we can rename it by renaming the ActiveSheet.
Alternatively, you could manually copy a sheet using by first reading the original sheet into MATLAB and then writing it back to Excel as a new sheet. This is discussed in more detail at: