Control Multiple Slicers With Macro

Hi
I want to make a macro or macros that will run when the file is opened. These macros need to do the following:
1. Select Day Slicer and click on the Multi Select Button so that Multi Select is ON
2. Select the MONTH Slicer and do the same thing
3. Select a specified cell and change the value in that cell from YES to NO
4. Select another specified cell which is empty

I have found that no matter which technique I use for sequencing these steps, I can only get one Slicer selected and have its MultiSelect button set to ON.
I have tried:
All steps in one macro
Separate macros for each step with the next macro called at the end of the previous one
Listing all the macros in one 'on open' workbook macro

Any help would be greatly appreciated
Raz Ellen