Hi! Hoping someone can help with this...

I found this very nice formula in another post that converts a Base-36 # to decimal:
=IF(A1="","0",SUMPRODUCT(POWER(36,LEN(A1)-ROW(INDIRECT("1:"&LEN(A1)))),(CODE(UPPER(MID(A1,RO W(INDIRECT("1:"&LEN(A1))),1)))-48*(CODE(MID(A1,ROW(INDIRECT("1:"&LEN(A1))),1))<58 )-55*(CODE(MID(A1,ROW(INDIRECT("1:"&LEN(A1))),1))64 ))))

Can someone write me the opposite code in a similar Excel formula format?
ie, converting a # as high as 999999999999999 (15 9's) to Base-36 ... I'm using web converters right now as an alternative and the Base-36 converted # is "9ugxnorjlr"

If the code, like above, can accommodate other Base-X conversion (by changing the "36"), that would be even better, thanks!

-Jason