Is it possible to derive a formula from a table like this?:
if date in colum A contains the text "feb" then add all figures correspondant in colum B (=183)
____A______B__
1l 1-jan-05....l...23
2l 2-jan-05....l...64
3l 3-jan-05....l...67
4l 6-feb-05....l...43
5l 5-feb-05....l...60
6l 6-feb-05....l...80
7l 7-mar-05...l...67
8l 8-mar-05...l...52
9l 9-mar-05...l...43
if date in colum A contains the text "feb" then add all figures correspondant in colum B (=183)
____A______B__
1l 1-jan-05....l...23
2l 2-jan-05....l...64
3l 3-jan-05....l...67
4l 6-feb-05....l...43
5l 5-feb-05....l...60
6l 6-feb-05....l...80
7l 7-mar-05...l...67
8l 8-mar-05...l...52
9l 9-mar-05...l...43