Select value (rate) based on four constants (effective date) and one variables (period)

I have to track payments due each month and I am looking for a way evaluate this spreadsheet line by line and insert the appropriate rate into col Q based on the period and effective date of the four rates. The code needs to look at the four effective dates (cols J, L, N, P) and chose the appropriate rate (cols i, k, m, o) based on the effective date of the rate and the period (C1). This is a short version of 103 column spreadsheet. This spreadsheet needs to revaluate and re-post the rate as the period (C1) is changed each month.

J, L, N and P would not always have a date, in some case a lease would start "AFTER" the first of the month in that case you would have a date in J (pro rate effective), in some cases you would have only a 1 year lease beginning on the first day of the month, thus a date in L (1 year effective), in some cases you will have a two year lease beginning on the first of the month in that case dates in N (year.1 effective) & P (year.2 effective). The variables are dates in J & L, dates in J, N & P, date in L only, dates in N & P only.

Answers are:
Q4 =1,100 (pro-rate date (J) is less than the period date (C1), 1 year date (L) is less than period date (C1) but greater than pro-rate date (J) and N & P are NULL, thus (L) is TRUE 1,100)

Q5 = 1,300 (pro-rate date (J) is less than the period date (C1), 1 year date (L) is NULL, year.1 date (N) is less than period date (C1) and year.2 date (P) is less than the pro-rate date (C1) but greater year.1 date (N), thus (P) is TRUE, thus 1,300)

Q6 = 1,400, (pro-rate date (J) is NULL, 1 year date (L) is NULL, year.1 date (N) is less than period date (C1) and year.2 date (P) is greater than the period date (C1), thus (N) is TRUE 1,400)

Q7=1,400, (pro-rate date (J) is less than the period date (C1), 1 year date (L) is NULL, year.1 date (N) is equal to period date (C1) and year.2 date (P) is greater than the period date (C1), thus (N) is TRUE 1,400)

Q8 = 400, (pro-rate date (J) is greater than the period date (C1), 1 year date (L) is NULL, year.1 date (N) is greater period date (C1) and year.2 date (P) is greater than the period date (C1), thus (J) is TRUE 400)

Q9 = 1,600, (pro-rate date (J) is NULL, 1 year date (L) is NULL, year.1 date (N) is equal to period date (C1) and year.2 date (P) is greater than the period date (C1), thus (N) is TRUE 1,600)

Q10=1,700, (pro-rate date (J) is NULL, 1 year date (L) is equal to period date (C1), year.1 date (N) is NULL and year.2 date (P) NULL, thus (L) is TRUE 1,700)