.Rows() will not accept a string value - vba

Question

I'm writing a routine to insert some rows, and to copy over some values.
The amount and position of the rows that need to be inserted are dynamic and stored in variables.
I know I can insert rows by using Activesheet.rows("2:12").Insert shift:=xlDown
Now as the 2 and 12 are dynamic I declared variables of datatype Long to hold those values. For example:
Dim Startvalue as Long
Startvalue = 2
Dim Lengthofinsert as Long
Lengthofinsert = 10
Dim Endvalue as Long
Endvalue = Startvalue + Lengthofinsert
Then I wrote the following: Activesheet.rows("""" & Startvalue & ":" & Endvalue & """").Insert shift:=xlDown which results in a type mismatch.
Using debug.print("""" & Startvalue & ":" & Endvalue & """") the result of this is "2:12", exactly the same as I entered in my first insert() statement above.
I thought perhaps first storing the string as a string variable might help, but that unfortunately also results in the same type mismatch.
Now I figure rows should take some sort of Array or Range as argument, but how do I convert my two Long's into that?

Answer 1

just use
ActiveSheet.Rows(Startvalue & ":" & Endvalue).Insert shift:=xlDown
You don't need the "" because Startvalue & ":" & Endvalue is already a string (the long values automatically cast into a string due to the concatenation with &).
Same like
Dim MyRows As String
MyRows = Startvalue & ":" & Endvalue
ActiveSheet.Rows(MyRows).Insert shift:=xlDown
Or as #Chronocidal pointed out in the comment:
Compare the outputs
Debug.print("""" & Startvalue & ":" & Endvalue & """") 'output: "2:12"
Debug.Print("2:12") 'output: 2:12

Answer 2

Have you created Thisworksheet? It's not mentioned in your declarations.
Assuming you have,
Try
ThisWorkSheet.rows(Startvalue & ":" & Endvalue).Insert shift:=xlDown
Otherwise try:
Activesheet.rows(Startvalue & ":" & Endvalue).Insert shift:=xlDown