If the login doesn't fit into your program:
Change the sub-account login so that it contains the minimum number of characters (currently six).
If you need to reduce the character count further, you can shorten the connection by removing some elements. For example, in a login like:
xxxxx-zone-custom-region-us-st-arizona-session-IdSess-sessTime-120
you can remove the "zone-custom" part, leaving only the necessary information. As a result, a shorter version will be:
xxxxx-region-us-st-arizona-session-IdSess-sessTime-120
In this way, the login and session will become more compact while retaining all the important information for proper proxy operation.