You need to access computer which is not in a domain?

No problem Cool

Here is the code:

var token: Cardinal;
dwResult: DWORD;
nr: TNETRESOURCE;
sl: TStringList;
begin
  nr.dwType := RESOURCETYPE_DISK;
  nr.lpProvider := nil;
  nr.lpLocalName := nil;
  nr.lpRemoteName := '\\computername\sharedfolder'; 
//\\computername\sharedfolder\ will not work - just with ExcludeTrailingPathDelimiter  
\\also will not work \\computername\d$\folder\ - we need just \\computername\d$
  dwResult := WNetAddConnection2(nr, 'password', 'user', 0); //watchout username and pass are on strange positions, at least for me
  if (dwResult = NO_ERROR) or (dwResult = ERROR_ALREADY_ASSIGNED) or (dwResult = ERROR_SESSION_CREDENTIAL_CONFLICT) then
  begin
    sl := TStringList.Create;
    sl.LoadFromFile('\\computername\sharedfolder\file.txt');
    ShowMessage(sl.Strings[1]);
    FreeAndNil(sl);
  end;
end;

Taken from here.