Can I conditionally UNLOCK a cell?

I have protected my workbook, leaving certain cells
unlocked so users can value them. Based on the values
that my user choose, I will auto-populate a tangent cell
with either YES or NO (this cell will be locked).

Question: If the auto-populated cell value is YES, I want
to (a) auto-populate an subsequent tangent cell with a
value (defined from a validation list) and (b) unlock the
cell to allow my users the ability to change the auto-
populated value I defaulted. However, if the auto-
populated cell value is NO, I will (a) default the value
of the subsequent tangent cell but (b) keep the cell
locked. Any ideas of how to do this? Note: if need be,
I have provided some examples to better explain
my "hopeful" worksheet processing.

Ex. 1
A1 = 200 (unlocked so user can select from list)
B1 = Car (unlocked so user can select from list)
C1 = YES (locked cell; auto-populated with YES based on
A1,B1 condition)
D1 = defaulted value - but change-able. Since C1 = YES,
D1 is value to something I default from a validation list
and (b) is now "unlocked" so my users can change the
default value if it is inappropriate.

Ex. 2
A1 = 200 (unlocked so user can select from list)
B1 = Bike (unlocked so user can select from list)
C1 = No (locked cell; auto-populated with NO based on
A1,B1 condition)
D1 = defaulted value - and unchange-able. Since C1 = NO,
D1 is value to something I default from a validation list
and (b) remains "locked" so my users cannot change the
default value.

Hi
if I understood your requirements correctly this is not possible
without VBA (using an event procedure). As a starting point see:
http://www.cpearson.com/excel/events.htm

--
Regards
Frank Kabel
Frankfurt, Germany

"Chris" schrieb im Newsbeitrag
...
I have protected my workbook, leaving certain cells
unlocked so users can value them. Based on the values
that my user choose, I will auto-populate a tangent cell
with either YES or NO (this cell will be locked).

Question: If the auto-populated cell value is YES, I want
to (a) auto-populate an subsequent tangent cell with a
value (defined from a validation list) and (b) unlock the
cell to allow my users the ability to change the auto-
populated value I defaulted. However, if the auto-
populated cell value is NO, I will (a) default the value
of the subsequent tangent cell but (b) keep the cell
locked. Any ideas of how to do this? Note: if need be,
I have provided some examples to better explain
my "hopeful" worksheet processing.

Ex. 1
A1 = 200 (unlocked so user can select from list)
B1 = Car (unlocked so user can select from list)
C1 = YES (locked cell; auto-populated with YES based on
A1,B1 condition)
D1 = defaulted value - but change-able. Since C1 = YES,
D1 is value to something I default from a validation list
and (b) is now "unlocked" so my users can change the
default value if it is inappropriate.

Ex. 2
A1 = 200 (unlocked so user can select from list)
B1 = Bike (unlocked so user can select from list)
C1 = No (locked cell; auto-populated with NO based on
A1,B1 condition)
D1 = defaulted value - and unchange-able. Since C1 = NO,
D1 is value to something I default from a validation list
and (b) remains "locked" so my users cannot change the
default value.