Create Metric Account from Specific SQL database pulls

I'm not sure about what you mean by "populating a dimension member". It seems like you already have a way to retrieve the list of members you're interested with; if you want to expose that list to cube views, you can place that logic in a Custom Member List in a Finance Business Rule file, which will generate the list for views or other components. A basic example of a custom list is available here or in Snippets; you then reference it from a cube view with this syntax:

A#Root.CustomMemberList(BRName = YourBRName, MemberListName = YourListName, SomeParameter=SomeValue)

Or this, which is equivalent:

A#Root.[YourBRName, MemberListName, SomeParameter=SomeValue]

 There are examples of this also in Snippets.

Is that what you were after...?