Besides using the Excel Plug-in to generate RTD links, you can create RTD links by directly entering the RTD formula.
Simple Quote Format (Streaming Quote Only)
=RTD("ESRTD",,"<Symbol>","<Field>")
Extended Quote Format (Streaming or Snapshot Quote)
=RTD("ESRTD",,"*Q","<Symbol>","<Field>") - Streaming Quote
=RTD("ESRTD",,"*S","<Symbol>","<Field>") - Snapshot Quote