"Jim Thomlinson came the closest - create a user-defined function. But
then,
what magic incantations do I have to invoke to use it in a cell
formula?
Thanks."

If you put the code in a regular module in the desired worksheet, or in
an add-in if you want the function available to all/several worksheets,
you call the function like you would any other worksheet function
=mydateadd(arg1,arg2,arg3,arg4)


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MrShorty
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