We know from the list of Europeans in Bengal (IOR/O/5/26:1793-1809), that in
1793 he was living in Bow Bazar Street, Calcutta, was working as an Examiner in the
Board of Revenue and had been in Bengal since 1786/7, where he was before this, is unknown.
We also know that the Board of Revenue changed its remit after the 1793 reforms as part of the Permanent Settlement, it may be that he was effectively out of a job, that he may have been paid off. But somehow he had sufficient money to get married in 1794 and then in 1796 to buy his Ensign (entry to officership of the British Army). Did this money come from his EIC job or from his marriage to Mary. Mary was previously married to John Lowis (who also lived in the same street as Lawrence in 1793), who as a Wine Merchant would not have been bankrupt!
Whilst he worked for the Board of Revenue, the Bengal Calender of 1790 and 1792 record him under the section "List of European subjects who are not in the service of the Company", which would imply two things, that his father at least was British and the status of the Board of Revenue was such that he was not actually on the Company books, hence his absence in the HEIC records where I have looked The research pages shows where I have checked in the British Library, OIOC records and found nothing.