Relative path for a file - javascript

Hi.

I'm trying to set a file path in one of the scripts and it has to be a relative path.

I've been having some difficulties with the format I'm using.

File location: C:\Users\Public\testrepo\TC.Project\Test\Datafiles\1234.xlsx

I was trying to use the relative path as:    "\\TC.Project\\Test\\Datafiles\\1234.xlsx"     OR "/TC.Project/Test/Datafiles/1234.xlsx"

but doesn't work.

Any help would really be appreciated.

Thank you

Abhi