Macro to open latest file within a folder

Hi Guys,
I have case where there are excel files arranged like this within a folder. For example:-

XA11_df01.xlsx
XA11_df02.xlsx
XA11_df03.xlsx
.
.
XB11_df01.xlsx
XB11_df02.xlsx
.
.
YA11_df01.xlsx
YA11_df02.xlsx
.
.
YB11_df01.xlsx
YB11_df02.xlsx
.
.

All these files are located in one folder. I want to write a macro to open the latest excel files based on lastmodified date and time for each file name like XA11, XB11, YA11, YB11. I only want to do this for excel files (".xlsx") within a folder as there are other pdf files also in the folder. I want macro to open the latest file for first file name run my code on it , then open latest file for second file name and run my code on it so on.


Any help will be highly apprecited.

Thanks.
Roop