Function And Linked Server

I have my own function, which I can use:

declare @dt as datetime
select @dt='20040121 12:22:33'
select * from index_gold_iif(@dt)

When I try do it from linked serwer:

declare @dt as datetime
select @dt='20040121 12:22:33'select * from
lewiatan.e_.dbo.index_gold_iif(@dt)

I have massage:
Server: Msg 170, Level 15, State 31, Line 2
Line 4: Incorrect syntax near '('.

Did server can't see function from linked server? Is it true or I have done
some error (what)?

Marek

PS. all done as "sa" user, linked server linked with sa account