Using MAPI to change attachment filename

Using MAPI to change attachment filename

Using COM and MAPI, we are trying to rename an attachment in an MSG file.
I've got everything working (we get the IAttach interface, then use
GetProps and SetProps), but I'm nervous about making sure that we change
all the properties we need to.
Does anyone know if the following is sufficient?
Check and if present, change value of:
PR_ATTACH_EXTENSION_W PR_ATTACH_FILENAME_W PR_ATTACH_LONG_FILENAME_W
PR_DISPLAY_NAME_W
Also, will setting the _W values automagically set the _A values? I think
yes, but can't find and reference documentation that says one way or
another.