Ditch the textbox, get it directly

[vba]

Dim wkbPrime As Workbook, wkbMacro As Workbook, wkbCallSheet As Workbook, _
strNTuser As String
Dim filepath As String

filepath = CreateObject("WScript.Shell").SpecialFolders(16)

Set wkbPrime = Application.Workbooks.Open(filepath & "\frmPrime.xls")
Set wkbMacro = Application.Workbooks("User Form.xls")
Set wkbCallSheet = Application.Workbooks.Open _
("\\fil-nw-312\QA_787_Vis\Daily Metrics\Call_sheet\Call-Sheet-Analysis.xls")
[/vba]