How do i test if a form (not MsgBox) button is clicked?

Hello,
I have an Excel form that displays records from an external file. The form has these buttons to traverse the records:

[<<] , [ < ] , [ > ] , [>>] (viz. btnFirst, btnPrevious, btnNext, btnLast)

The buttons are not assigned to macros; instead they are part of the VBA code (below). How do I properly check for a button press?

Thank you.

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Dim btnFirst, btnPrevious, btnNext, btnLast As Buttons   'is this still valid?
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Flag = 1
Max = 100
Index = 5

GetRecord:

'   At this point the program finds the record at Index and displays it...
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'   ...then waits for a button click

	Do While Flag <> 0
        	If btnFirst.Click Then      'problem is here; how do I test?
            		Index = 1
           		GoTo GetRecord
        	End If
        
        	If btnPrevious.Click Then
            		Index = Index - 1
			GoTo GetRecord
        	End If
        
        	If btnNext.Click Then
            		Index = Index + 1
			GoTo GetRecord
        	End If

        	If btnLast.Click Then
            		Index = Max
 			GoTo GetRecord
        	End If
	Loop
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