Custom weighted average function for 3d ranges

I have a Lotus 1-2-3 spreadsheet which I created a long time ago, and which I need to convert to Excel. It has many uses of the @weightavg function and they are applied to 3d ranges. In trying to convert this to Excel, I got pointed in the direction of using the indirect function. This gets cumbersome, so I'm considering writing vba code to do this since I can imagine it will be useful for other things as well. I'm hoping someone can get me jump started on the best way to go about this.

This is what works:
=SUMPRODUCT(N(INDIRECT("'"&$Q58:AE58&"'!"&"H22")),N(INDIRECT("'"&$Q58:AE58&"'!"&"H67")),N(INDIRECT("'"&Q58:AE58&"'!"&"B51")))/K11

I would like to create a generalized version of this as a user defined function which would allow me to simply specify the 3d ranges I wish to use to do the sumproduct on.