string $str = "This is some text";

string $subStr;

// Get 5 characters starting at index 3

$subStr = `strMid $str 3 5`;

print $subStr; 

// Should be "s is "

// Get rest of string from index 8

$subStr = `strMid $str 8 -1`;

print $subStr; 

// Should be "some text"