Jestli tě dobře chápu, tak hledáš v nápovědě tohle:
You can use the + and - operators to increment and decrement the offset of a character pointer. You can also use - to calculate the difference between the offsets of two character pointers. The following rules apply.
If I is an integer and P is a character pointer, then P + I adds I to the address given by P; that is, it returns a pointer to the address I characters after P. (The expression I + P is equivalent to P + I.) P - I subtracts I from the address given by P; that is, it returns a pointer to the address I characters before P. This is true for PChar pointers; for PWideChar pointers P + I adds SizeOf(WideChar) to P.
If P and Q are both character pointers, then P - Q computes the difference between the address given by P (the higher address) and the address given by Q (the lower address); that is, it returns an integer denoting the number of characters between P and Q. P + Q is not defined.
Pozn. character pointer = PChar