Dear John, there are quite a few examples from 1809 in Austria that may fit your criteria (though many were initiated by the Austrians):
• Archduke Charles sent a note to Napoleon in April (this was handed over at the French outposts, not an officier parlementaire per se).
• During June there were several rounds of negotiations on prisoner exchanges, carried out by exchanges of notes between Berthier and his Austrian counterpart, Wimpffen (the two did not meet). Some of these involved exchanges of officers and men (e.g., the 65e de Ligne captured at Regensburg); another set dealt with exchanging Metternich for the former French consul in Vienna, Claude Dodun (this exchange took place in Hungary).
• On the eve of Wagram, Charles sent FML Weissenwolff to Berthier ostensibly to discuss further prisoner exchanges (actually a peace feeler); Weissenwolff met and dined with N, but was (understandably) detained as the second crossing of the Danube was about to commence.
• Weissenwolff was then returned to Charles on 9/10 July, not with a specific written message but certainly carrying the impression of the courteous treatment he had received and N's openness to some kind of talks. (Massena, in his correspondence, referred to Weissenwolff as a 'général parlemantaire' even though this was not his exact function.)
• Also on 10 July, Prince Liechtenstein was sent by the Austrians to N to sound him out on peace.
• Shortly thereafter, Charles propose a battlefield ceasefire at Znaim by sending FML Hennequin de Fresnel to Pajol with this offer (and on to Marmont, the French commander on site).
• The following day, N sent an officer (not clear who) to the Austrians accepting the battlefield ceasefire--this led to direct negotiations between Berthier and Wimpffen. All of this back–n–forth resulted in the ceasefire that evening with Marbot and his Austrian counterpart, the younger Konstantin d'Aspre, carrying out the dangerous mission of communicating the ceasefire orders to the two engaged armies. (Liechtenstein finally found N that night.)