MVclerk wrote:How do I set up an account so that his relatives donations will go towards his mission fund?
Church HQ will automatically take the $400 from your Branch Missionary Fund. (Donations for the missionary should be paid on the Tithing Slip to "Ward Missionary".) Within MLS, you can create a subaccount for the Ward Missionary to be the Elder's name. That way it is easier to assign the money to a particular missionary when you get a donation for him, and you know what the "balance" is.
The details are found in MLS, under Help -> Help; Inside the Help Window, look for: MLS Help -> Financial Policies -> Missionary Financial Support.