I have some extensive code that is formatting data in an excel
spreadsheet for import into another program. There are times when we
will use a default value for a field called "Collectability Code", but
sometimes the user will want to manually populate that column. If
we're using a default, my code can insert the appropriate code without
any input from the user other than indicating whether they want to
input them manually. So, my question is this: How can I pause
execution of the code to allow for manual entry in a certain column,
then resume when the user is ready and I've validated the data?
Furthermore, if the data they enter is invalid (or missing), I'll need
to give the user the opportunity to correct their entries before
finalizing the data for import (basically loop through any invalid/
missing records until it passes the validation process).

Thanks in advance for any assistance,
Jana