This person was a first cousin of Mirza Ghulam Ahmad and plays a role at various points in his life:It is possible that he was the commander of the 50 horses and cavaliers raised by Mirza Ghulam Murtaza (father of Mirza Ghulam Ahmad) for the British.
Probably, he is the 'Imad-ud-Din' referred to as a childhood friend in Seeratul Mahdi and a travel companion
Seerat-ul-Mahdi:"My mother told me that his holiness, the Promised Messiah, one day, during his youth, went to collect the pension of his grandfather (700 rupees - Seeratul Mahdi, Vol. 1, P. 131). Following him was a person by the name of Imamuddin. When he received the pension, Imamuddin mislead him and took him outside Qadian. They roamed about from place to place. When his holiness had squandered all he had, Imamuddin deserted him leaving him alone and left for some other place. However, his holiness, the Promised Messiah, did not return home for shame and for fear of infamy. And since his grandfather's desire was that he be employed somewhere, he went to Sialkot and got himself employed for a miserably low salary (ten rupees a month)." (Seeratul Mahdi, Vol. 1, P. 43; by Mirza Bashir Ahmad)
(cited from 'The Sepoy Rebellion of 1857-59 by AH Amin')
Pages-41 & 42-Chiefs and Families of Note in the Punjab-Volume Two, by Sir Lepel Griffin and revised by W.L Conran and H.D Craik, Civil and Military Gazette Press, Lahore-1910)