search for file, if exist, mark cell and create link

hi!

i would like to ask someone to help me program macro. i have only beginner knowledge about programming in excel.

i have excel file, i attached it.

this is how looks my directory:

screen.png

in excel is column D, which contains details name, in folder DETAILS is *.pdf file with same name, for example DSB-100.pdf.

i would like to check is file exist, then mark cell N in green and create link to this file if not, then mark cell red.

of course it should work like, if checking data in D3 then mark N3, if checking data in D4 then mark N4 and so on.

i hope that commented clear enough.

thanks in advance.