Code:
alias base64 {
var %indexTable = ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/
var %input = $regsubex($$1, /(.)/g, $base($asc(\t), 10, 2, 8))
var %n = $regex(%input, /(\d{6})/g)
var %i = 1
while (%i <= %n) {
var %translate = %translate $+ $mid(%indexTable, $calc($base($regml(%i), 2, 10) + 1), 1)
inc %i
}
return %translate
}