I'm assuming here that when you say "song", you actually mean "tune"; I know of no songs (tunes with words) of this title, but there are several pipe pieces that could be what you are looking for.  We are in Pibroch territory here, though, which is too specialised for me!  I doubt if even the basic melodies are available on the Web; all the references I've found have been to performances, recordings and printed sources.  In case it's of any help at all, here is some background; firstly, from The MacCrimmon Family From 1740 To 1936 by George C.B. Poulter (1936), found at  The MacCrimmon Family Website:

"DONALD MOR MACCRIMMON, son of Padruig Donn [MacCrimmon] was born c.1570.  He is said to have returned to his kinsfolk in Ireland to be perfected as a piper and to have then composed the lament for the Earl of Antrim; but the lament probably dates from a later journey when he would have accompanied Sir Rory Mor's five hundred clansmen sent to assist red Hugh O'Donell, who was in rebellion against Queen Elizabeth about the year 1595.  He composed MacDonald's Salute and Failte nan Leodach or MacLeod's Welcome to celebrate the reconciliation between the MacLeods and their MacDonald neighbours after the battle of Bencuillein early in the seventeenth century."

The Piobaireachd Society  mentions MacDonald's (or Duntroon's) Salute (Failte Mhic Dhomhnuill) and Lady Margaret MacDonald's Salute (Failte Baintighearna Mhic Dhomhnuill).

James Stewart's Tune Index  also mentions James MacDonald's Salute, MacDonald Of Duntroon's Salute, Lady MacDonald's Salute and dates MacDonald's Salute to 1609.

I've also seen mention of a Failte Chloinn Domhnuill, which may or may not be the same as one of the above.

Of course there may be a song of which I am unaware (maybe someone has set words to the Urlar [base melody] of one of these, or just borrowed the title for a song of their own), in which case the above will probably be of no interest to you...

Malcolm