First step is to figure out why Excel is seeing it as a number. Maybe the cells are formatted as text;
Is there any way of converting them besides hand-typing them manually, I wonder.
Reformat the cells and then use "Text to Columns" to get Excel to recognize they've been changedor there are spaces before or after the numbers;
Use find/replace to remove them and use Text to Columns or use TRIM to fix them in an other columnThey might have invisible characters that are not spaces;
Find out what they are using =CODE(MID(A1, location,1)) and then use SUBSTITUTE to remove themSometimes just adding 0 to them works, sometimes it's much more complex.