See http://en.wikipedia.org/wiki/Base_36 for some useful information. I
would approach it as follows:

1) Determine the length of the string.

2) For each character in the base36 string from 1 to n (n being the
length of the string), store it as a variable in memory, convert it
using the Wikipedia conversion table, store it in a new variable name,
and the adjacent cell.value = newvar1 & newvar2 & ... newvarn.

3) Then move to a new cell and repeat.