passing parameters into stored procedures classic asp

I've asked a similar question before and although I've attempted to fix my previous code i now end up with an error "Arguments are of the wrong type, are out of acceptable range, or are in conflict with one another". I want to pass a single character as a parameter to query a database then use recordset to print out to a webpage. My classic asp code is below

Set objCon = CreateObject("ADODB.Connection")
Set objRS = CreateObject("ADODB.Recordset")
set objComm = CreateObject("ADODB.Command")

objCon.ConnectionString = "Provider=SQLOLEDB.1;Password=xxxx;Persist Security Info=True;User ID=xxxx;Initial Catalog=Movies;Data Source=xxxx-PC"
objCon.open objCon.ConnectionString

objComm.ActiveConnection = objCon.ConnectionString
objComm.CommandText = "Paging_Movies"
objComm.CommandType = adCmdStoredProc

Set objParameter = objComm.CreateParameter
objParameter.Name = "alphaChar"
objParameter.Type = adChar
objParameter.Direction = adParamInput
objParameter.Value = "a"

objComm.Parameters.Append objParameter

set objRs = objComm.Execute

Also my stored procedure is below -

CREATE PROCEDURE Paging_Movies
@alphaChar char(1)
AS
if @alphaChar = '#'
    select * from Movies where movies like '[^a-z]%'
else
    select * from Movies where movies like @alphaChar + '%'

Perhaps you're adding the parameter twice. Try to replace:

objComm.ActiveConnection = objCon.ConnectionString
objComm.CommandText = "Paging_Movies"
objComm.CommandType = adCmdStoredProc

Set objParameter = objComm.CreateParameter
objParameter.Name = "alphaChar"
objParameter.Type = adChar
objParameter.Direction = adParamInput
objParameter.Value = "a"

Set objParameter = objCommand.CreateParameter ("alphaChar", adChar, _
    adParamInput, "a")

objComm.Parameters.Append objParameter

with just:

objCommand.CreateParameter ("alphaChar", 129, 1, 1, "a")

Edited as your comment suggests to use the numeric values for adChar (129) and adParamInput (1) from the W3Schools CreateParameter page.