Excel VBA: How to concatenate variant array elements (row numbers) into a range object?

I did research this question but could not find the specific answer I was looking for and am actually even more confused at present.

I created a macro that would run through rows on a sheet and run boolean checks on a number of cells in each row that looked for the presence or absence of specific values, or calculated the outcome of a specific inequality. On the basis of those checks, the macro may or may not pass the row number into a specific array. That part is working fine.

My issue is, now that I have the row numbers (stored in variant arrays) - I cannot figure out how to properly concatenate that data into a range and then take a bulk excel action on those items. What I'd like to do is create a range of those values and then delete all of those rows at once rather than looping through.

My macro is on my work computer, but here's something I wrote that should explain what I'm trying to do:

    Sub Test()
Dim Str As String
Dim r As Range
Dim i, a As Integer
Dim Count As Integer
Dim RngArray()



Count = ThisWorkbook.Sheets("Sheet1").Cells(Rows.Count, "A:A").End(xlUp).Row
ReDim RngArray(Count)


a = 0
For i = 1 To Count
    If Not i = Count Then
        RngArray(a) = i
        Str = Str & RngArray(a) & ":" & RngArray(a) & ", "
        a = a + 1
    ElseIf i = Count Then
        RngArray(a) = i
        Str = Str & RngArray(a) & ":" & RngArray(a)
        a = a + 1
    Else: End If
Next i

Set r = Range(Str)'Error Can Appear here depending on my concatenation technique
Range(Str).EntireRow.Delete 'error will always appear here

End Sub

I've combined a few steps here and left out any Boolean checks; in my actual macro the values in the arrays are already stored and I loop from LBound to UBound and concatenate those values into a string of the form ("1:1, 2:2, 3:3, ...., n:n")

The reason why I did this is that the rows are all over the sheet and I wanted to get to a point where I could pass the argument

Range("1:1, 2:2, 3:3, ..., n:n").EntireRow.Delete

I think it's clear that I'm just not understanding how to pass the correct information to the range object. When I try to run this I get a "Method Range of Object Global" error message.

My short term fix is to just loop through and clear the rows and then remove all of the blank rows (the macro keeps track of absolute positions of the rows, not the rows after an iterative delete) - but I'd like to figure out HOW to do this my way and why it's not working.

I'm open to other solutions as well, but I'd like to understand what I'm doing wrong here. I should also mention that I used the Join() to try to find a workaround and still received the same type of error.

Thank you.