how can I check if some files exist in other PC ?

I use

?file('\\PC1\MyApp\Data\cust.dbf')     && exist, return .T.

but it's highly not accurate, it will always return .T. although the file is not exist,
as long as I have it in my own PC

?file('\\PC1\MyApp\Data\cust1.dbf')     && not exist, but return .T., because I have it
                                         && in my own PC

any way to know for sure? please advise.

thanks

Robert