I have a workbook which will be added new worksheets to by others. The
worksheet names are all month names.

I want to do a sumif according to the name of the worksheets, i.e. according
to the month specified by the worksheet name.

I am using the following formula, and it doesn't work:
=SUMIF(MID(CELL("filename",A1),FIND("]",CELL("filename",A1))+1,255),
"=*Sept*", STATISTICS:BLANK!C1)
with an intention to sum up the C1's in all sheets with the sheet's name
including the string "Sept".

Could anybody please help me out with this, thanks a bunch in advance!
Theresa