Is it possible to make rows editable in a readonly data display grid?

Hello All,

I have a grid for displaying the data and as the number of columns are very huge around 50, I can not use editable gridcontrol. So is there a way to make a specific cell editable based on the index selection. Lets say for example, My design looks like below

ENO    Name    Age

1         abc       40

2         pqr       30

3         xyz       10

Now, Lets say we have a validation where user can not insert age below 20. So based on that criteria the last row is not acceptable. So for that we want to provide drop down column to the user where the list of indexes available in which there is any validation issues and on the basis of that index selection the record at the cell would appear into editable component. In this case the index would be 9. That means the dropdown will show index 9 to user and when they click on the index. The field at index 9 should appear in editable format so that user can change its value