[xRyder]

Not sure if this will help, but you can use strdel and strins.
Example: (I found it somewhere around here)

pawn Code:

new s1[128] = "I'm eating cakes";
new s2[] = "shitting";

strdel(s1, 4, 10);
strins(s1, s2, 4);
    
print(s1);