I think you do not understand the effect of a double extension.
Neither do I, but I expect a significant change to the old fashioned DOS rules.
You do not say if you are using Win 98 under Command.com, or Win XP upwards with CMD EXE.
This demonstrates that a 4 byte long file named 2852.09.rvt is included in the mask *.????.rvt;
and that mask is used by both the DIR and the DEL commands of CMD.EXE under Win XP
C:\Documents and Settings\Dad>dir *.????.rvt
Volume in drive C is ACER
Volume Serial Number is EC16-8702
Directory of C:\Documents and Settings\Dad
29/03/2010 19:56 4 2852.09.rvt
1 File(s) 4 bytes
0 Dir(s) 9,094,397,952 bytes free
C:\Documents and Settings\Dad>del *.???.rvt
C:\Documents and Settings\Dad>dir *.???.rvt
Volume in drive C is ACER
Volume Serial Number is EC16-8702
Directory of C:\Documents and Settings\Dad
File Not Found
C:\Documents and Settings\Dad>
AS a matter of interest, Command.com under Win XP does the same, i.e.
C:\DOCUME~1\DAD>dir *.????.rvt
Volume in drive C is ACER
Volume Serial Number is EC16-8702
Directory of C:\DOCUME~1\Dad
29/03/2010 20:10 4 2835.09.RVT
1 File(s) 4 bytes
0 Dir(s) 9,094,377,472 bytes free
C:\DOCUME~1\DAD>del *.???.rvt
C:\DOCUME~1\DAD>dir *.???.rvt
Volume in drive C is ACER
Volume Serial Number is EC16-8702
Directory of C:\DOCUME~1\Dad
File Not Found
C:\DOCUME~1\DAD>
But I suspect Win 98 under Command.com will be a totally different matter.
Alan