Do you know for certain that he was ordained in Scotland rather than in Ireland? I don't know anything about the Presbyterian churches in Ireland but in Scotland most of them seem to have published lists - often called "Fasti" - a bit of Latin meaning list. At the time you mention, if he was in Scotland he might have been a minister of the Church of Scotland, of the Relief Church, of the Associate Presbyterian or possibly the Cameronians or Reformed Presbyterian Church. The information about the Relief Church and the Associate Presbyterian church is held in a large 2 volume set called The History of the United Presbyterian Church (these 2 churches came together to form the UP Church.
I know that published information about the ministers of these churches is available in the Edinburgh Central Library and I would normally offer to check for you but I am unlikely to be going there within the next few weeks.
Sorry its so complicated. I wondered where in Scotland this minister was born. If he was born in Galloway (Wigtownshire or Kirkcudbrightshire, he might not have spent much time in Scotland. This area is very close to Ireland and lots of people went back and forth.
Perhaps you should put a posting on the Ireland board - probably someone could tell you about Irish sources for Presbyterian Ministers
Regards
Jessden