Change Starting point of Totalizer

I am using RSlogix 5000
Have one input from a flowmeter.

Sometimes there is a known about of product in the line. I need to account for the 28 gallons of product in the line in the batch control sequence.

Normally, the meter starts at "0" and counts up to the cut-off and all is good. But sometimes, there is 28 gallons of material in the line that needs to be accounted for. When the system gets to the point where it will be transferring the material that has 28 gallons already in the line, I would like to start the meter count at "28" and not "0". Then when the totalizer reaches the target amount, the system will shutoff with the correct amount transferred.

I.E.
System needs 100 gallons
There are 28 gallons of material in the line
Start the totalizer at 28
System counts up to 100 and cuts off.

We are using the "Fill_Flow_Instruction" add-in to do pump control.

I know I could just subtract the 28 from the totalizer setpoint and it would be OK, but the totalizer is viewed from an HMI and the HMI needs to display the transferred amount of 100 and not the adjusted amount of 72.

Is there an easy way to start the totalizer at 28 and not 0?

Thanks

Could you use the reset value?

ResetValue
REAL
The reset value input. The reset value of Total when OperResetReq or ProgResetReq transitions from false to true.
Valid = any float
Default = 0.0

Not familiar with the instruction mentioned. Can you not just write 28 to the total on startup when the condition is true?

is "fill_flow_instruction" an AOI?

BUT: when the pump is shut off there will be 28 gallons in the pipe to be there for the next run.

If you add the 28 then run and shut off your output will be short 28 gallons.