From wikipedia Intel Hex (the obvious source for such informations)
04, Extended Linear Address Record, allowing for fully 32 bit addressing (up to 4GiB). The address field is 0000, the byte count is 02. The two data bytes (two hex digit pairs in big endian order) represent the upper 16 bits of the 32 bit address for all subsequent 00 type records until the next 04 type record comes. If there is not a 04 type record, the upper 16 bits default to 0000. To get the absolute address for subsequent 00 type records, the address specified by the data field of the most recent 04 record is added to the 00 record addresses.
So the formula is (linAddr <<16) + addr
or in your case ($0001 << 16) + $FFC0
And for the case of 02/Extended Segment Address Record, the formula changed to
(segAddr << 4) + addr