Close the file by keyboard shortcuts by vba

vba is placed in a seperate file 1.xlsm
now what i need
there can be 2-3 or it can be 4 files opened along with this 1.xlsm
i will be in 1.xlsm file & i will ran the macro
now what i need is when i ran the macro it should go to next open file and use ALT+ F4(this is shorcut key to close the excel file) and that will be close and then again go to next open file and use ALT+ F4 and again if there is a file then do the same do till all files are closed except 1.xlsm
and i wanted to inform u sir by doing ALT+ F4 only my file is closing and i want to close all the file by this way only sir
So plz have a look into this problem and help me in solving this problem
we have to solve this problem only by vba only sir so plz help sir & mam