In foxpro grid we've got a column bound to field ( N ) . Just wondering whether it is doable ?

Expected behaviour :
Column hour_minute :

No application flag set
Entered 4.5 saved as 4.5 and shown as 4.5

Flag is set to minutes
Entered 4.30 saved as 4.5 in a table, kept to be shown as 4.30 in a grid.

We assume rounding to quarters either for decimals or real minutes entered. 0.25 , 0.5 , 0.75 or respective 0.15, 0.30 , 0.45 minutes.
Introducing another expression based read-only column which shows value based on application flag and bound column is always converted to decimals may be a solution.