According to Santokh Singh (a poet historian) Lalla Beg, a resident of Kabul, was a general of the army of Shah Jahan. In December 1634, he led a large army against Guru Hargobind Sahib. This battle was fought in three phases, at Mehraj, Mahal Kalan and the surrounding areas. A very large number of of the Mogul soldiers and Sikhs were killed in these battles. His sons too were killed in this battle. But, this is just concoction. There was no Moghul general of this name.
(Dr Harjinder Singh Dilgeer)