Facing problem with execute function

The execute function is not taking the arabic chars in..or nvarchars in

what i did is execute(@.sql)
where @.sql is a nvarchar

Assuming it as a insert statement to a table the chars are appearing as ?
where as the chars when inserted using a plain insert query comes clearly in arabic

set @.sql=insert into test values('arabic chars');
insert into test values('arabic chars'); works good plainly
but when called through execute it flops
execute (@.sql)
I even tried by inserting the @.sql value to the DB the query formed is shown that it is in arabic.

i tried using this but syntax error occured
EXECUTE sp_executesql @.stmt =N' (@.sqls)',
@.Farms = N'@.sqls nvarchar(max)',
@.sqls = @.strintest

The above is working only when we give the query

with dynamic values to be passed in

You have to ensure the value string shoule be prefixed with N.

(example) all the quires are working properly..

Code Snippet

insert Into testarabic values(N'???? ????? ??????? ???? ??? ???? ?????. ????? ?????? ?? ?????? ?? ???? ??????')

Exec ('insert Into testarabic values(N''???? ????? ??????? ???? ??? ???? ?????. ????? ?????? ?? ?????? ?? ???? ??????'')')

Declare @.SQL as NVarchar(1000);

Select @.SQL=N'insert Into testarabic values(N''???? ????? ??????? ???? ??? ???? ?????. ????? ?????? ?? ?????? ?? ???? ??????'')'

Exec (@.SQL)

The following quires will fail,

Code Snippet

insert Into testarabic values('???? ????? ??????? ???? ??? ???? ?????. ????? ?????? ?? ?????? ?? ???? ??????')

Exec ('insert Into testarabic values(''???? ????? ??????? ???? ??? ???? ?????. ????? ?????? ?? ?????? ?? ???? ??????'')')

Declare @.SQL as Varchar(1000);

Select @.SQL=N'insert Into testarabic values(N''???? ????? ??????? ???? ??? ???? ?????. ????? ?????? ?? ?????? ?? ???? ??????'')'

Exec(@.SQL)