Copy/insert A Row To A Position Defined In A Form

I'm not an experienced VBA programmer, so hopefully (and probably) for you it's easy to tell me how to do it: So far, I copy a row(1) to another position (7) with this macro:

Rows("1:1").Select
Selection.Copy
Range("A7:BU7").Select
Selection.Insert Shift:=xlDown
Range("A7:BU7").Select
Application.CutCopyMode = False
Range("A7").Select

That works well so far. Now what I want to do is, to use a form and enter a number and have the row 1 inserted in this row number (because it should not always be in row 7). For example that i can insert 38 in the form and it will copy the row number 1 to row number 38. I tried this:

Range ("frm_insertrow.txt_rownumber").Select