I'm currently writing a history of the 5th/60th.

On page 145 of 'Passages in the early military life of General Sir George T. Napier,' dealing with the battle of Bussaco there is the following:

'One poor German officer in the French army came to make inquiries respecting his brother, who was in our service in the 60th Eegiment, which
was at that time composed principally of foreigners, and upon looking about he found him dead, the poor fellow having been killed.'

Assuming this account is true the three members of the 5th battalion who were killed at Bussaco were:

Private John Witting from Hanover, Germany, a labourer who joined the battalion in March 1806
Private John Kowalsky from Galicia, a shoemaker, who joined from the foreign depot September 1807
Private Jacob Stephan from Lugar, Hungary, another labourer who had been with battalion since formation in 1797, and had entered British service in 1795.

Witting seems the most likely candidate but the term German was used very loosely for almost anyone from northern or central Europe at the time.

Can someone point me towards an online resource where I may find lists of French officers? Of course it is more than likely that the brother was in one of the client state's armies.

Thanks
Rob