One way to select a cell without having to reinvent the
wheel, via a modless form, is to use:

Dim myRange as Range
Set myRange = Application.InputBox( _
"Select a cell", Type:=8)


But if your form is used to do more than just pick a cell,
then to prevent code from executing until the OK button is
clicked, you can use a public boolean flag and a DoEvent
within a Do While loop.

In your module's declarations section at the top:
Public OKButtonClicked as Boolean

In the VBA routine that calls the form:

Private MySubroutine()
'some code
OKButtonClicked = False
frmMyForm.Show
Do While Not OKButtonClicked
DoEvents
Loop
'some more code
End Sub

And finally in your form's OK button:
Private Sub cmdOK_Click()
'Your Code
OKButtonClicked = True
End Sub


Or as an alternate to the boolean flag, I often hide the
form after the OK button is clicked, so I might use:

frmMyForm.Show
Do While frmMyForm.Visible
DoEvents
Loop
'More code here


-----Original Message-----
Suppose I want to use a form which prompts the user to
select a cell and press an OK buttom on the form when
ready. I figure the form must be modeless, but how do I
prevent the code following the statement
frmMyForm.Show
from executing until the OK button on the form has been
clicked?

TIA, Arne
.