names to numbers

Hi,

I have problem with change of names of the months to numbers. however, this is just a part of what I am doing. I will go with whole process step by step, pls also see the excel table attached:

1. I one of the columns I have this kind text "2010/jul/29". this is not being seen as date by excel, but as text. each cell has different data
2. so, to make excel see it as a text, I need to break it into its constituent and then use the formula Date
3. this formula has 3 subcategories: year, month, day. and excel needs numbers, not text to make it work. so the problem occures in month part. that is "jul" (or any other, like "jun", "sep"
4. I need a macro or update formula, that could change the text to number, and I need to add it to my Data formula.
5. I have placed the ready formula in the excel table attached. I do not paste it here, because my formula is not in english, but your excel will read it in your language. date/text is in A1, formula is in C1
   
   thanks for your help in creating of new formula or macro.