I guess your 2nd macro is changing a value which should fire the change event? As Rory inferred, your Application.EnableEvents should be set to True at the end of your change events code. It should also handle errors so that it is set back to True.
It is hard to help without seeing code or an example workbook.
You could set a Modular Sub to take input parameter as the Target range. Then your other macro could just Call it like your change event macro would. Obviously, you would have to call it with the Target range directly. e.g.
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