Conditional / SUMIF

[wlnba]

Hi, I'm hoping someone can help me with my worksheet involves phasing of expenses. Any assistance would be very much appreciated. Thanks!!!

Col A, rows 2-6 are Descriptions (i.e. A, B, C, D, E)
Col B, rows 2-6 is the phasing start month.
Col C, rows 2-6 is the phasing end month.

There are three types of expenses: Included (I), Pass-Through (PT) and Absorbed (AC)

Col D, rows 2-6 is the type of expense for each of the 5 descriptions.
Col E-I, row 1 are five different dept within our company.

Description A has a phasing term of months 1 - 48. Expense type is I.
Description B has a phasing term of months 6 - 48. Expense type is PT.
Description C has a phasing term of months 12 - 48. Expense type is I

In Cols L - BG, row 1 I've the full timeline (horizontally) for months 1-48.

In Col K, rows 2-6 I've entered the five descriptions: A, B, C, D, E. These are all for expense types I.
In Col K, rows 7-11 I've entered the five descriptions: A, B, C, D, E. These are all for expense types PT.
In Col K, rows 12-16 I've entered the five descriptions: A, B, C, D, E. These are all for expense types AC.

In cell L2, I need a formula that will take the sum of all I type expenses that are incurred in month 1 for description A.
In cell L3, I need a formula that will take the sum of all I type expenses that are incurred in month 1 for description B.

Skipping on....
In cell L7, I need a formula that will take the sum of all PT type expenses that are incurred in month 1 for description A.
In cell L8, I need a formula that will take the sum of all PT type expenses that are incurred in month 1 for description B.

Skipping on....
In cell L12, I need a formula that will take the sum of all AC type expenses that are incurred in month 1 for description A.
In cell L13, I need a formula that will take the sum of all AC type expenses that are incurred in month 1 for description B.

Thanks again for the time you've put into helping me with this.