Custom expression / calculated column not producing expected results
I am working with a crosstable trying to achieve a forecast value that is a calculation of Month To Date admissions divided by todays date and then multiplied by the number of days in the month. I have the calculated columns as such:
MTD - case
when (Month([REG DATE])=Month(DateTimeNow())) and (Year([REG DATE])=2020) then [ENCOUNTER ID]
Todays date - Day(DateTimeNow())
Days in month - if((month([REG DATE])=10) or (month([REG DATE])=12) or (month([REG DATE])=8) or (month([REG DATE])=7) or (month([REG DATE])=5) or (month([REG DATE])=3),31,if(month([REG DATE])=2,28,30))
I created a new calculated column called "Forecasted Admissions" and used this formula: UniqueCount([MTD]) / [Todays date] * [Days in month]
When I tried to add it to the cross table as a cell value, it wants some sort of aggregate function placed on it but I just need the literal value returned. So I tried to take the formula above -UniqueCount([MTD]) / [Todays date] * [Days in month]- and put it directly into the Cell Values expression. It is saying the expression is invalid.
Can someone help me achieve this? I really want it to be listed beside the other numbers in my screenshot as you see but is this possible??
Sample dataset attached along with my table screenshot to help in aiding my explanation.