Well, i've found a solution after various articles and answers in foruns.
To add custom design editors to controls created on .NETCF basically we need a file XMTA (like a manifest file), specifying the comments and categories and editors, etc. Yupiii!!
See this link for more info, this article show how to add attributes into .net cf controls.
Design Time Attributes .Net CF
Design Time Attributes .Net CF
Microsoft XMTA File Example
<property name="Line1DisplayMember">
<defaultvalue>
<type>System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a</type>
<value>Name</value>
</defaultvalue>
<category>Data</category>
<description>The Property contain the data for line 1</description>
<editor>
<type>System.Windows.Forms.Design.DataMemberListEditor, System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a</type>
<BaseType>System.Drawing.Design.UITypeEditor, System.Drawing, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a</BaseType>
</editor>
</property>
Conclusion,
Create a XMTA(manifest) file and specify the values. When you compile the project, the .net compiler makes two libraries. The your library and other with .asmmeta.dll in the name ( it contains the manifest used by Visual Studio Designer to edit your control).
I hope it helps others people :)
Thanks
Dan Elliott