I promise I'll make something fun and useful with them

I think these are all I need:
(1) Convert Tropical longitude and latitude to right ascension and declination (and the reverse).
(2) Convert RA and declination (and the other variables, e.g., RAMC and latitude) into PV longitude.
Thirdly, I think there is a generalizable version of the above which allows transformation between any two coordinates sets. This would be useful for experiments, e.g., calculating positions of planets projected against the meridian by great circles through EP-WP, to determine mundane aspects between horizon and prime vertical.
But the first two are what I really need.
My immediate plans are to create an Excel spreadsheet that, among other things, would let planet positions from one chart, in one era, be converted to a mundoscope within the context of a second chart from another era. Simple example: What are the mundoscope positions of your natal planets within your current lunar return? To get this, we need to precess your natal positions to the current SLR date, recalculate RA and Dec, then use this to calculate the prime vertical longitude for the RAMC and latitude of the current SLR.
Here is what the spreadsheet would look like: At the top, you can type in RAMC, geographic latitude, and current and birth SVP - perhaps obliquity of the ecliptic - all available from SF easily). You can set up a permanent spreadsheet for yourself, with your own positions, where one or two of these numbers are all you would ever have to change.
The body of the spreadsheet would have a row for each planet, in which you type the Sidereal longitude and latitude. (Make one for yourself and save it; or save it as a separate tab in the Excel spreadsheet.)
Immediately, it will give the Mundoscope positions (PV longitudes) of each planet.
To put it in the framework of another chart - say, your current SSR or SLR, you just edit the "current SVP" and RAMC fields and, bingo, you instantly have the Mundoscope positions of your natal planets inside the current SSR or SLR. (It's the only way you can REALLY tell how angular your natal planets are in the return chart, or whether there are mundane aspects between them. Everything we do at present is a trick to estimate it.)
There are also other uses. Instant relocation angularity... ways of calculating primary directions... and more.
If someone could just please provide me with the equations I've lost?
Thanks!