Thanks for your reply to my posting regarding, linking a text box to
an external workbook. You informed me that the destination file would
need to be opened first.

However - I still have the problem regarding linking the text box
within a userform to the external opened file.

I can easily link the text box to a cell in the same workbook as the
userform by using the following statement

Range("A5").Value = txtMyTextBox.Value

although I wish to link the input of this text box to a cell in a
worksheet of the external Excel workbook.

So whatever is typed into this text box gets dynamically entered into
the external file/sheet/cell.

Do you know how I can achieve this?

Thanks again for your help Tom.