A StartBit method sets the iOutput variable to the bit distance from the start of the layer. And Move is our example here:
START_BIT
METHOD Move__
/* moves the pointer the requested number of bits, negative
* numbers move back */
CODE
iOutput = iofsbitCurrentPosition + iParam1 * SizeOfUnitsInBits (eParam2);
ENDCODE
PARAM "Amount to move" int
PARAM "Units" list {Bit Bits Nibble Nibbles Byte Bytes Octet Octets Word Words Dword Dwords Qword Qwords} = Bytes