自己解决
function tform1.fexists(d,s:string):boolean;
var n:integer;
begin
try
NMFTP1.ChangeDir(d);
nmftp1.ParseList:=true;
NMftp1.list;
except
exit;
end;
for n:=0 to nmftp1.FTPDirectoryList.name.Count -1 do
nmftp1.FTPDirectoryList.name[n]:= uppercase(nmftp1.FTPDirectoryList.name[n]);
n:=nmftp1.FTPDirectoryList.name.IndexOf(s);
if n>-1 then result:=true
else result:=false;
end ;