Unfortunately I can't provide an example, it's confidential patient data and can't exactly be sanitized. I can however provide what character/column the field begins and ends at. The field starts at colum 308 and ends at column 327. Instead of being blank, I want the field to contain "See Free Text" without the quotes.

No I do not want to change the size of the line in any way. The field, nor the line containing the field can not change in size, otherwise the importer has a fit.