Expanding %userprofile% within a Set Variable within an if Statement. Batch

I have something similar to the following...

set /p dir=Specify Path:
 if exist %dir% (
 echo ok
 ) else(
 echo not ok
)

If the user enters a path or variable like %userprofile%

when %dir% is used %userprofile% is not expanded within.

for example

set dir=%userprofile%
echo %dir% :: this does not expand
call echo %dir% :: this does expand
cd %dir% :: does not expand
call cd %dir% :: expands

but how would I have the path expand within a if statement.

Been banging my head on this one and i'm not really understanding DelayedExpansion.

Thanks.