Future Forecast Update - Leaving Historical Forecast as previously set

On a weekly basis I update the forecast dates for several tasks for the week(s) ahead.  Any tasks that were not completed will be reforecast plus any new tasks to generate the coming week(s) forecast.  I have then created a second table in Excel where I COUNTIF the number of sites with a forecast date each day (excluding any site that has an actual already) and populate the number of forecast tasks each day.

In the Excel formula I check the reference date is today onwards and only update the count of target dates for those tasks not for any dates in the past , by doing this any previous forecast number is maintained in the table.  (Hopefully that makes sense!). Snips showing the Data export and the Targets table below:

I am currently then using the Targets Table in Power BI to visualise Daily and Cumulative Targets.

I want to generate the Targets Table so that when I export the updated forecast data once a week, the targets table automatically updates for future forecast count and the historical target data remains intact.

Sure that it is easy but as new to Power Query and Power BI, struggling to get my head around how to reference, filter and count from another table, (or maybe an even easier solution) so hoping someone can help?!?