Question on ConvertToString/Delimiter

Good morning group.
Webmethods 7.1
I got pretty confused yesterday, so I wanted to ask you guys if you can
clear something up for me when it comes to the ConvertToString service.
Customer told me that they wanted end of record delimiter to be CRLF (no
problem) and the field delimiter to be tab delimited (problem). Okay, I
have a schema that references a data dictionary. The data dictionary
contains fields that involve an actual start and end position. On the
schema in the Flat File definition section, I selected Delimiter, then
selected carriage return line feed as Record Character and in the Field or
Composite field, picked tab.

Record worked, but no tab delimiter to be found anywhere in the data after
convert to string is run. Still showing a hex 20 between the fields which
means “space”. Next tried placing a tab delimiter on the convertToString
service itself in the delimiters/field section. Nothing, still no tab
delimiter. This went on for a long time yesterday with me trying to figure
out how to do the customer’s request, but no matter what, I could not get
the tab delimiter to show between fields. Looking at other code in the
system, it seems that this works fine when it comes to data that doesn’t
involve an actual start / end position (the nth field stuff). Is there
some sort of rule that I’m not aware of that says that you cannot change
the field delimiter when it comes to fields that involve an actual
start/end position or am I missing something here?

Is there another trick to get the job done? I can’t use replace (change
all hex 20 spaces to hex 09 tabs) because the tab is only supposed to
happen between fields and in circumstances where the field is blank, the
blank field should not be converted to a tab. I do not know if I’m
experiencing a bug or if I’m just not thinking about this correctly or if
the customer made an unreasonable request.
Thanks for your help. __.___.