Hi, you have to use parameter object to pass it to command object.
see the code below
'for input parameters
Dim ip_para1 As New ADODB.Parameter
Dim ip_para2 As New ADODB.Parameter

'define input/output parameter(s), if any, types in sync with sql

Set op_rate = cmd.CreateParameter("output", adCurrency, adParamOutput)
cmd.Parameters.Append op_rate
Set ip_para1 = cmd.CreateParameter("input", adInteger, adParamInput)
cmd.Parameters.Append ip_para1
Set ip_para2 = cmd.CreateParameter("input", adVarChar, adParamInput, 4)
cmd.Parameters.Append ip_para2
cmd.CommandText = "YourProcedure"

'assign values to ip paras
ip_para1.Value = CLng(DataCombo1.BoundText)
ip_para2.Value = Text2
'execute you procedure
cmd.CommandType = adCmdStoredProc
cmd.Execute
'cmd(0) wud return value of output para, if any
mrate = IIf(IsNull(cmd(0)), 0, cmd(0))