You can edit custom-defined macros. You need at least Application Manager permissions to edit local (application-level) macros and Administrator permissions to edit global (server-level) macros.
To edit custom-defined macros:
From Enterprise View or a custom view, select an Essbase Server.
Right-click, and select Edit, and then Macros.
In the Custom Defined Macro Manager window, select a macro, and click Edit.
In the Edit Macro dialog box, edit one or more fields.
Click OK.
Essbase updates the macro.
create macro (MaxL) in the Oracle Essbase Technical Reference