Convert Text Comments To Date In VBA

I have a situation where textual comments are entered into a cell where the comments are supposed to begin with a date in mm/dd format. Some enter all 5 characters but some enter m / d in if appropriate to the date, e.g., 9/6 vs 09/06.

I'm trying to take the left 5 characters and compare that to the current date - 7 to ID aged comments and highlight that cell. I currently do this by populating a variable LastUpdate (dim as string) with the first 5 characters, then run this IF statement.

If LastUpdate < Date - 7 Then
Range("O" & i).Select
Selection = "Comments over 7 days old."
End If

This works find except in situations where there is a zero for the first character after the "/", such as "11/05." The code doesn't properly calculate the date and assumes it's old. "11/5" works just fine. I thought I could try translating the variable into a proper date. I "borrowed" this formula from another post herein: =DATE(2012, MID(N12,1,FIND("/",N12)-1), MID(N12,FIND("/",N12)+1,2)). This works fine as a formula to translate the characters into a date but I don't know how to do this same thing in vba.