Help in copy, search in another workbook, refer, paste

I am looking to search for a list of data from a given spreadsheet in a masterlist with the data scattered around and then update the cells in the masterlist with the data in the given spreadsheet. The process of doing so is as described. In the given spreadsheet, i copy the value in lets say C2 and go to the masterlist and search for the value. Once the value is found, i go back to the given spreadsheet and copy a few cells to the right of it and paste it a few cells away in the masterlist. I am able to do it for the first row and loop the macro but can't seem to change the text to search to another value. Really appreciate if somebody could help take a look at my code to see where it can be improved on.

Sub Macro4()
'
' Macro4 Macro
'
Do While IsEmpty(activecell) = False

    activecell.Select
    Application.CutCopyMode = False
    selection.Copy
    Windows("masterlist.xlsx").Activate
  Cells.Find(What:="text to search for", After:=activecell, LookIn:= _
        xlFormulas, LookAt:=xlPart, SearchOrder:=xlByRows, SearchDirection:= _
        xlNext, MatchCase:=False, SearchFormat:=False).Activate
   Windows("givendata.csv").Activate
    activecell.Offset(0, 2).Select
    Range(activecell, activecell.Offset(0, 11)).Copy
    Windows("masterlistxlsx").Activate
    activecell.Offset(0, 5).Select
    ActiveSheet.Paste
    Windows("givendata").Activate
    activecell.Offset(1, -2).Select

    Loop

End Sub

Thanks in advance!