Is there a requirement to use a macro? This could be done in a separate
column using ordinary functions and then overwrite the original column  if
needed.

If you realy want to use a macro  the the code would be something like...

... Select/set the range
... Loop through the range
... ... cell  text = mid(cell text,1,3)

Is there a requirement to use a macro? This could be done in a separate
column using ordinary functions and then overwrite the original column  if
needed.

If you realy want to use a macro  the the code would be something like...

... Select/set the range
... Loop through the range
... ... cell  text = mid(cell text,1,3)