Something

public str_replace(search[], replace[], source[]) //By Tratulla
{
	new newnick[256];
	new newlen;
	for (new i; i < strlen(source); i++)
	{
	    if (strlen(search) > 1 && i != (strlen(source) - 1))
	    {
	        new matched = 1;
	        new start = i;
	        for (new s; s < strlen(search) && matched == 1; s++)
	        {
	            if (source[i] != search[s] && s == 0)
	            {
	                newnick[newlen] = source[i];
	                matched = 0;
				} else
				{
		            if (source[i] == search[s])
		            {
		                i++;
		            } else
		            {
		                matched = 0;
					}
				}
	        }
	        if (matched == 0)
	        {
	            for (;start <= i; start++)
	            {
	                newnick[newlen] = source[start];
	                newlen++;
	            }
	        } else
	        {
	            for (new r; r < strlen(replace); r++)
	            {
	                newnick[newlen] = replace[r];
	                newlen++;
	            }
				i = (start + (strlen(search) - 1));
	        }
	    } else
	    {
			if (strlen(search) == 1 && source[i] == search[0])
			{
			    for (new r; r < strlen(replace); r++)
			    {
			        newnick[newlen] = replace[r];
			        newlen++;
			    }
			} else
			{
			    newnick[newlen] = source[i];
			    newlen++;
			}
		}
	}
	newnick[newlen] = EOS;
	return newnick;
}