G'day Dan

The closest I could come to converting this into what resembles a date
format is this

Assume:

18400314 = A3

place this in B3 =RIGHT(A3,2) ' this will give you the Day = 14
place this in C3 =MID(A3,5,2) ' this will give you the Month = 03
place this in D3 =LEFT(A3,4) ' this will give you the year = 1840

To comine them into one

place this in E3 =B3&"/"&C3&"/"&D3 ' this will give you this:

14/03/1840

The only drawback is that this is text, not date.

One of the many MVP Guru's may provide something more suitable.

HTH
Mark.