Bill,
You can do this using mostly built-in features and one feature you're sure to hear more of in the future. First, I suggest creating a directory of your personal equations. Do this by typing:
'MYEQ' CRDIR This makes a directory for you. Press its name on the menu keys to change directories to it.
One way to create custom keys is to create many individual objects in a directory. If you do this, change to the directory, find the object and press the menu key. Another way is to use the custom menu key - CST . Press that key and all the programs appear although it's about the same as having the names in one directory. The advantage is that only your equations appear - no variable names. (Using the HOME diectory is ok but it will fill-up with too many objects).
Each program object would look like the following:
<<
'your equation'
'EQ' STO
#3BE54h SYSEVAL
>>
The number before the SYSEVAL must be the same as shown. That begins the SOLVR menu.
For a custom menu, look up the feature in your owners manual. If you need more advice, contact me directly.
Joe