Wouldn't the value be 618.965 rather than 618.950? If not, where did the 50 come from?
Ok, so the value is X'00000000618965'. You're correct that it's a packed data value without a sign (it's NOT binary and it's NOT PD) - it has 14 digits. DFSORT doesn't have a built-in format for a PD value without a sign.
how to convert this data to S9(9)V9(3) COMP-3
That would be a 12 digit PD value. Note that PD values do not actually have the decimal point - it's implied. So the conversion you asked for would be from X'00000000618965' to X'000000618965C'.
To do that conversion, you need to remove the first 2 digits on the left and add a sign at the end. I assume the sign would always be positive (C) - right?