Increment number at end of string - vba

Question

My string is in the format Cells(i, 6) & ("-000") & (q). Here Cells(i,6).value is an integer.
I want to add 1 to q, from the string it is in.
ElseIf k > 0 Then
Sht1.Cells(erow, 3) = CInt(sht3.Cells(i, 5).value) + 1
Sht1.Cells(erow, 4) = CInt(sht3.Cells(i, 6).value) + 1
Sht1.Cells(erow, 1) = Sht1.Cells(erow - 1, 1).value + 1
End If

Answer 1

Try to replace your code with this:
If k > 0 Then
Sht1.Cells(erow, 3) = CInt(sht3.Cells(i, 5).value) + 1
Debug.Print CInt(sht3.Cells(i, 5).value)
Sht1.Cells(erow, 4) = CInt(sht3.Cells(i, 6).value) + 1
Debug.Print CInt(sht3.Cells(i, 6).value)
Sht1.Cells(erow, 1) = Sht1.Cells(erow - 1, 1).value + 1
Debug.Print Sht1.Cells(erow - 1, 1).value
End If
And see where it breaks. Take a look at the immediate window. Probably the value is not a number.
If you edit the code a bit, you may get what you want:
Public Sub TestMe
If k > 0 Then
Sht1.Cells(erow, 3) = IncreaseWithOne(sht3.Cells(i, 5).value)
End If
End Sub
Public Function IncreaseWithOne(strValue As String) As String
Dim myVal As Long
myVal = Split(strValue, "-")(1)
IncreaseWithOne = Split(strValue, "-")(0) & "-" & Format(myVal + 1, "0000")
End Function
But it is really better, if you edit your question to what you want. E.g., you want to split the string 25-00001, cast to integer and increment the second part and return 25-00002. Because adding integer to string is not supported by any programming language.

Answer 2

From your other question (linked at bottom), we know that the digits you want to increment are always the right-hand 4 characters, so you could use Right to isolate the numerical part. I also think you have now taken a different approach and are storing the increment value separately. For reference though, this is how you could have done it:
Dim myString as String
myString = "25-0003"
' Assume there is always a single dash before the number to increment
' This means we can use Split to create two parts, before and after "-"
Dim myVal as Integer
myVal = Val(Split(myString, "-")(1))
' >> myVal = 3
myVal = myVal + 1
' >> myVal = 4
myString = Split(myString,"-")(0) & "-" & Format(myVal, "0000")
' >> myString = "25-0004"
So to edit your actual code, implementing the above code as a function, it becomes
Sub ThisIsYourSub()
If k > 0 Then
Sht1.Cells(erow, 3) = IncrementString( sht3.Cells(i, 5).value )
Sht1.Cells(erow, 4) = IncrementString( sht3.Cells(i, 6).value )
Sht1.Cells(erow, 1) = IncrementString( Sht1.Cells(erow - 1, 1).value)
End If
End Sub
Function IncrementString(ByVal myString as String) as String
' You should have some error handling in here!
Dim myVal as Integer
myVal = Val(Split(myString, "-")(1)) + 1
IncrementString = Split(myString,"-")(0) & "-" & Format(myVal, "0000")
End Function
Split Documentation:
https://msdn.microsoft.com/en-us/library/office/gg278528.aspx
Your other question, including details on using the Format function as above:
Standard pattern of string is like 16-000q. Use leading zeros to create 4 digit string from q