Using the Values of a Formula for another formula

I have A, B, C and D. A is the result of B+C but now I want to use the result of A for an IF formula in D. How can I use or grab only the value that was throw in the Sum of B+D withouth copying, only the value in another cell?. Is there a complete formula that transform that value on a text value to use it in another formula?

Im confused by this. Are you saying that A=B+C or A= B+D? If the former, then you can place any formula in D that uses the result from A. If its the latter then you can't, because neither A or D can be evaluated unless the value of the other is known.
Perhaps if you explain what your trying to do in more detail or post an example spreadsheet, someone will be better placed to help.

If the formula in A1 is =B1+C1, and you need to work with the text equivalent of the output of A1, you have a couple options. If you need just the text version, you can use the TEXT function.

=TEXT(A1,"0.00") will give the output of A1 to two decimal places.
=TEXT(A1,"0%") will give the output of A1 as a percentage.
Etc.

Option 2 involves using CONCATENATE...

If A1 outputs the number 33.2, =CONCATENATE("The value of A1 is ",A1,".") outputs:

The value of A1 is 33.2.

Does this answer your question?