The original DL4YHF code was written for Microchip MPASM assembler, which was bundled with MPLAB 8 and older MPLAB X versions. (IIRC MPASM support was dropped from MPLAB X as of v 5.40). The link to Antonio's (StarNiell's) Github you provided is a version ported to pic-as, the XC8 assembler, and will require a recent MPLAB X and XC8 installed, neither of which are likely to run well, if at all on a legacy Win7 PC. IMHO ignore Antonio's port, which adds very little functionality, install MPLAB v8.92:
https://ww1.microchip.com/downloads/en/DeviceDoc/MPLAB_IDE_8_92.zip and base your version on the code from DL4YHF's site or one of the links he provides to others' versions of his counter from 2018 or earlier.
However the PIC16F628 is a very old 18 pin PIC, without an ADC, so freeing up enough pins to encode three different offset selections would be difficult - the original design even had to resort to a diode/transistor NAND gate to drive the fifth digit's cathode. (If it had an ADC, you could use a resistor ladder to encode the offset selection as an analog level on a single pin.)
How experienced are you with PIC assembler? Are you good enough to port the code to a PIC with more pins? e.g. the PIC16F883,
(which has 28 pins (24 I/O pins), more RAM, twice the program memory and is debug capable under MPLAB 8 with a PICkit 2 or 3) to allow you to simplify the automatic offset selection by having an individual select pin for each stored offset.
Personally I no longer regard rooting around in other's MPASM assembly code (even if very well commented) as a worthwhile use of my time. The price of larger faster MCUs has dropped so much that for one-off or small run projects, if the code need more than minor tweaks, its cheaper, quicker, and easier to re-implement the algorithm in C, on a sufficiently more capable MCU to get comparable performance.
N.B. Microchip dropped MPLAB 8 compatibility from the 8 bit PIC C compiler XC8 as of v1.34. There is a workaround for later XC8 v1.xx: https://forum.microchip.com/s/topic/a5C3l000000MRNlEAO/t335317 but by the final v1.45 they'd also stripped the required MPLABXC8.dll. Don't even think about using any XC8 V2.xx version under MPLAB 8!