I'm not 100% sure how access works with SQL Server, but I am gonna make the assumption that you can execute select statements in the usual manner by constructing an sql statement string, something like:
Code:
sqlstr = "select username from tbl_users"
connection.execute(sqlstr)
Based on the above you should be able to do something like:
Code:
sqlstr = "exec my_proc " & [forms]![form_a].[Combo4] & ", " & [forms]![form_a].[text12]
connection.execute(sqlstr)
Please note none of the above is exact code, and I am not 100% sure of Access's capabilities, but this should show a concept.
Hope this helps,
Faris