one value based on a many values

[crispbreeze19]

I have two tables, 4 fields A, B C and D. I want to set the D value to the number of 1s plus the number 7s that are between A and B on field C

D= the # 1s and 7s between the row numbers FieldA and FieldB in FieldC

I know a little VBA and macro stuff but not too too much