You need to create a routine that will go thru the all the forms in your app, checking each form to see if its name is equal to the name ( or description) of the form you selected from the grid. You can't use the Forms collections, since this only looks at forms that are currently open... instead you have to use Containers.... Something like this

For i = 0 to CurrentDb.Containers(1).Documents.Count -1
if (grdSelection) = CurrentDb.Containers(1).Documents(i).Properties(8).Value then
'you have found the right form description
DoCmd.OpenForm CurrentDb.Containers(1).Documents(i).Name
End If
Next i

Bash