I really didn't know how to do this, so I did it the long way, how could optimizing this be done? Its to convert Octodecimal (Base 18) to Decimal (Base 10):
length(Str1)->O
For(I,1,O)
sub(Str1,I,1)->Str2
If (Str2="0")
R+(0*18^(O-I))->R
If (Str2="1")
R+(1*18^(O-I))->R
If (Str2="2")
R+(2*18^(O-I))->R
If (Str2="3")
R+(3*18^(O-I))->R
If (Str2="4")
R+(4*18^(O-I))->R
If (Str2="5")
R+(5*18^(O-I))->R
If (Str2="6")
R+(6*18^(O-I))->R
If (Str2="7")
R+(7*18^(O-I))->R
If (Str2="8")
R+(8*18^(O-I))->R
If (Str2="9")
R+(9*18^(O-I))->R
If (Str2="A")
R+(10*18^(O-I))->R
If (Str2="B")
R+(11*18^(O-I))->R
If (Str2="C")
R+(12*18^(O-I))->R
If (Str2="D")
R+(13*18^(O-I))->R
If (Str2="E")
R+(14*18^(O-I))->R
If (Str2="F")
R+(15*18^(O-I))->R
If (Str2="G")
R+(16*18^(O-I))->R
If (Str2="H")
R+(17*18^(O-I))->R
End