I've never seen a VBA "Global" dimension statement like you are trying
to use. I just declare the variable outside of a SUB or FUNCTION to
make it global. For example:

Dim strName As String
Sub DoThis()
strName = Range("A1").Address
DoThat
End Sub
Function DoThat()
MsgBox "Name: " & strName
End Function

You can only use Global outside subs and functions.

For the record, you can only use Global in regular Modules, not Class
Modules or UserForms.

You can define a "Public" variable in the definitions section above the subs in
a module. It
is then available to all subs and functions.

Like this
Public strName As String

Sub DoWhatever()
...
strName = YourCodeHere
...
End Sub