Hope that works:

material wireframe
{
effect="
texture entSkin1;
DWORD wfcolor = 0xFFFFFFFF; // Change this to the wireframe color of your choice
technique wireframe
{
pass p0
{
TextureFactor = <wfcolor>;
// CullMode = None; // Uncomment if you want backface too.
FillMode = Wireframe;
ColorOp[0] = SelectArg1;
ColorArg1[0] = TFactor;
}
pass p1
{
FillMode = Solid;
ColorOp[0] = SelectArg1;
ColorArg1[0] = texture;
}
}
";
}