I don't know of a way to adjust shininess of specific areas on the playfield but you can change shininess of the entire playfield. See below. Replace textureName with the name of the texture of the playfield and value is a number. Specular level is the amount of light reflected off an object but the light has to come from a light source on the table so it can be reflected.
'[BAM] !texture = textureName
'[BAM] !shininess = value
'[BAM] !specularLevel = 10.0
There is another way to code the same thing with many textures along with adjusting specular level:
Sub SetTexParams(texNames, specLevel, shineLevel)
Dim texArray, oneTexName, tex
texArray = Split(texNames,",")
For each oneTexName in texArray
Set tex = xBAM.GetTexture(oneTexName)
If tex.isValid Then
tex.SpecularLevel = specLevel
tex.Shininess = shineLevel
End If
Next
End Sub
SetTexParams "BackWall,SideWall1B,SideWall2B,afm plastic hd 2 B,afm hd lt100 gold,card", 0.001, 0.001
Red is SpecularLevel and green is Shininess. Yellow are the names of textures separated by commas.
The FP editor also has a slider where you can adjust glossiness of the playfield.