Changing size of Char field

We are running Informix SQL 4.1 on a DEC Ultrix machine. There is a char field that currently has a length of 5 characters that we would like to change to at least 6 (7 might be safer), but I want to make sure this isn't going to somehow screw up the current database. This field is used in several different tables and reports (one table currently has 6000 rows, another has 66,000, and this is a required field in several tables). I know that if we decide to do this, every table/report that the field appears in will need modification (there is a way I could get around needing to do this, but in anticipation of future needs, if we're going to do it, now would be the time). Unfortunately we are without a DBA at the moment, so it is falling on to me. I know what needs to be done and how to do it (I think), I just don't know if I change the size of this field for a database we have been using for 10 years if things will get screwed up. Thank you for any advice. Lisa