Hi Stanislav,
There's no really simple and reliable way of doing this. One approach is
to use Automation. It would require VBA code in the AfterUpdate event
procedure of the textbox to
-launch Excel (or get hold of it if it is already running)
-open the workbook
-update the cell
-save and close the workbook.
That is straightforward using the techniques demonstrated in the links
below. But it will not work 100% of the time: for instance, if the
workbook is already open it may not be possible to update the cell or to
guarantee that the change will be saved.
An alternative approach (probably a better one, in my opinion) would be
to store the value in the textbox in an Access table, and then use a
macro in Excel to fetch the value from the table (again using
Automation) when it is needed.
This is a useful article giving the basics of controlling Excel from
Access:
http://www.mvps.org/access/modules/mdl0006.htm
Q123859 ACC: Sample OLE Automation for MS Word and MS Excel
http://support.microsoft.com/?id=123859
ACC2000: Using Automation to Create and Manipulate an Excel Workbook
(Q210148)
http://support.microsoft.com/?id=210148
ACC: Using Automation to Create and Manipulate an Excel Workbook
(Q142476)
http://support.microsoft.com/?id=142476
Using Microsoft Access as an Automation Server
http://support.microsoft.com/?id=147816
http://support.microsoft.com/?id=210111 (Access 2000 and later)
Also, search
www.mvps.org/access
