Substitute-func
Substitute find$ with sub$ when found in within$.
string Substitute(string within, string sub, string find[, int n = 0])
within
sub
find
n
Return the new string replaced find$ by sub$ in within$.
string new$=Substitute(abcdefabcdef,12,bcd,0)$; new$=; //Should return a new string: "A12EFA12EF".
Replace, Exact