Hmm...
If I am understanding you what I would do is
1) write the desired formula
2) With the cell containing the formula selected, Start Macro recorder
3) press F2 (to edit) and press enter
4) Stop recorder
5) Create command button and assign macro
Because the formula was in the selected cell, this macro should write the formula you just created in the current active cell
Start with that. If the formula is in R1C1 format you should be okay as long as the formula is always written the same way
Seems like there may be potential for errors but based on muy interpretation of your request, this may solve it.
Let me know
ps. a better way may be to use the Name Manager to write your formula in the way you do LAMBDAs..