alright should be simple enough.
You have your method for checking if the user does have access to the user role it is provided?
Lets call it UserHasRole for the sake of the example.
UserHasRole returning a boolean value.
so in your aspx page try using codeBlocks.
<![CDATA[<% if (UserHasRole(userrole,userID))
{%>]]>
Declare menuItem Here
<![CDATA[<%}%>]]>
UserHasRole might need to be declared in the codebehind of the page trying to access it. That is dependant on how your asp.net appplication in setup.