Finding last blank column for a specific row using row no and pasting the data

Hi,
I have two different files say 'File_A' & 'File_B'. I have copied the data from 'File_A', now I want to paste it in 'File_B'
The thing is my 'File_B' in in the format as attached. How do I paste it in the last blank column for a particular row..(say 102 row no)

Below is my code..but my data gets pasted in the previous column everytime I run it..say first time it gets pasted in column D, then in column C like that.

Please suggest the changes in my code.

Sub Test()

Workbooks.Open "C:\Data\File_B"
Worksheets("Sheet9").Activate
Worksheets("Sheet9").Select

Range("B" & Rows.Count).End(xlUp).Select
Range(Selection, Selection.End(xlToRight)).Select

Selection.Copy
Workbooks("File_B").Sheets("A1").Activate
Dim last_col As Integer

last_col = Cells(102, Columns.Count).End(xlToLeft).Select


Selection.PasteSpecial Paste:=xlPasteAll, Operation:=xlNone, SkipBlanks:= _
False, Transpose:=True
Application.CutCopyMode = False
ActiveWorkbook.Save

End Sub