Update file to add as last column

Shell Programming and Scripting
1

I need to update a text file within a loop so that the value is added creating a new column at the end. I cannot use paste because I dont know the number of files. If I use >> the value is added after the last row. Please help.

For example:

Input file:

Column 1   Column2
     -                 -
     -                 -
     -                 -

1st iteration,

Column 1   Column2   column3 
     -                 -            (new values)
     -                 -
     -                 -

2nd iteration,

Column 1   Column2   column3  Column4
      -                 -              -           (new values)
     -                 -              -
      -                 -              -

Or be more specific,
I have n files named F_1, F_2,....F_n each having one columns and same number of row. I have an in put file with one column and want to add columns of F_1 as 2nd column, F_2 as 3rd column ....

Input file:

Column 1
   -
   -
   -

Output file:

Column1    Column2      Column3     .   .   .   .   .   
                  (from F_1)    (from F_2) 
       -                 -              -
       -                 -              -
       -                 -              -
2

Did you try:

paste F_*
3

Thanks..
It helped