Polygrid questions

[Paul Dupuis]

I see I have the properties of a polygrid for:

pgColumns -- an array of all column properties

and

pgColumnWidths -- a comma delimited list of widths

There does not seem to be a distinct property just for alignments, such 
as pgColumnAlignments

What I need to do is change the width and/or alignment of a specific 
column (that can change which column based on data). I can se no way of 
doing this other than repopulating the pgColumns array

If I try

set the pgColumnWidths of widget "rwTableview" to 
"300,75,75,75,75,75,75,75,75"

for example, that seems to have no effect.

If I try to just change one element of the column array, such as

put "300" into tArray[1]["width"]; set the pgColumns of widget 
"rwTableview" to tArray, it replaces all the other column information 
(names, etc.) with defaults (as I would expect)

Am I missing some syntax that will allow changing the name, label, 
width, alignment, or whatever property desired of a single column 
without touching any of the other column data already set?