usRow (USHORT)
Row index of the item for which the attribute or attributes are queried. Rows have a value from 1 to the value of the usRowCount field. This value, which is the total number of rows in the value set, is specified in the VSCDATA data structure when the value set control is created.
usColumn (USHORT)
Column index of the item for which the attribute or attributes are queried. Columns have a value from 1 to the value of the usColumnCount field. This value, which is the total number of columns in the value set, is specified in the VSCDATA data structure when the value set control is created.
ulReserved (ULONG)
usItemAttr (USHORT)
This value depends on the VIA_* attribute or attributes specified for the value set item.
VIA_BITMAP
VIA_DISABLED
The selection cursor can be moved to an unavailable item by using either the keyboard navigation keys or a pointing device. This allows a user to press the F1 key to find out why that item cannot be selected.
VMERR_INVALID_PARAMETERS