Operating macros in excel

Hi, I'm reasonably new to matlab so please excuse me if this is a stupid question. I've been trying to use a function to operate macros in excel. I've found 'xls_run_macro' in file exchange. It seems to use a function called 'actxserver' that according to google is built in to Matlab's toolbox. However when I try and run 'xls_run_macro' Matlab tells me the following:

>> autosheet Undefined function 'actxGetRunningServer' for input arguments of type 'char'. Undefined function 'actxserver' for input arguments of type 'char'.

Error in xls_run_macro (line 73) Excel = actxserver('Excel.Application'); % open Excel as a COM Automation server

Error in autosheet (line 2) xls_run_macro('automatedspreadsheet.xls','Macro3')

Which I think means that it can't find the functions 'actxGetRunningServer' or 'actxserver'. Am I right? If so is there an extra toolbox that I need to download or another search path that I need to give Matlab? Thanks! Kit