Enterkng data on a specific worksheet using a userform command button

Something like

With Worksheets(me.ComboBox1.Text)
lngR = .Cells(.Rows.Count,"A").End(xlUp).Row + 1
.Cells(lngR,"A").Value = me.Textbox1.Text
.Cells(lngR,"B").Value = me.Textbox2.Text
End With