Mapping Variable

[kpmINFO]

Can some one advise me on a simple logic how I can achieve it in Informatica

I have a transformation with some data , if one of the port value is "False" I would like to add another port and assign "False" to it for all the rows.

Here is the illustration

data within a transformation
col1 col2 col3
a b true
b c true
d e false

if I find a "False" in the third col I would like to add another column and make it false

col1 col2 col3 col4
a b true false
b c true false
d e false false

I tried this with Mapping variable but this did not work as mapping Variables changes reflect for next session

can some one give me logic to achieve this

My other question is , is there a variable within informatica that could be used as a global veriable within a mapping. This variable chould be accessible within all the Transformations and changes to the variable wiothin one transformations should be reflected within other transformations. I dont think this is possible with Mapping Variables.