To do on a life server
-Load cheat engine and select operation arrowhead as the process (Its the computer symbol with the magnifying glass)
-Go in game withdraw money out of the atm (don't pick common numbers like $1, choose a value like $76543)
-On the right side choose exact value type float then search for you're value.
-There should be a few address and a couple that don't have a decimal place, if there a more than a couple pick a new amount.
-Move the values down to the editing box by double clicking.
-Select all the values then right click and then choose change value you change it to whatever value you please.
-This address changes every time your money changes from a transaction, so you will need to redo these steps every time you spend money.
And then you are done, when I get bored of Arma I will release my mod app that I use.