dialog box to input data?
 

I have a workbook which will be used by third parties, which is why must be
user-friendly and not be exposed to mistaken inputs. Once a month user must
input data in Sheet1 (is hidden) as follows:
A1=J
B1:B10=J48, J50...
in a way that should there's a typo not equal to the letter in A1, there's a
warning. Also, numbers following the letter must be in ascending order (not
necessarily in increments of 2), and finally, user *must* type 10 entries,
otherwise a message is given.
in C1:C6 again 6 entries (mandatory), same structure as above (K50, K52...)
letter being the one immediately after the one in A1, numbers in ascending
order.
I made a few trial with Input Box but only 1 entry is allowed. Am I right?
And I need that user enters *all* data in a row, with, I guess, a sequence of
dialog boxes, 3 in my case.
Is there a way to do this with formulas? Or only a VBA routine does the job?
Appreciate very much any help. Thanx!
--
Dan GSB
Asset Management - Rio