How to correct date format

I want to insert dates to my table as followed:
mm/dd/yyyy.

For now, I costumed the column to be set as such. However, while inserting new value - order of input is different - dd/mm/yyyy.
Example:
input: 29/09/2014
output: 09/29/2014

1. I want input to match the output, and not write one way and watch other (want to insert mm/dd/yyyy and watch the same).

2. Also, I want to change format existing "opposite" values (dd/mm/yyyy) to mm/dd/yyyy. I manged to do so with left-mid-right functions, but later when pasting them as values - excel wouldn't recognize them as dates.

See attached table. A more problematic dates are in the year of 2015 (line 1209 and down). Thorough explanation of solution will be much appreciated.

Droriley