ZDaemon ACS Extensions - ZD_GetSkinTopIndex

ZD_GetSkinTopIndex() function

This function will provide you with the top index of the installed skins. The syntax is:
int ZD_GetSkinTopIndex()
See ZD_GetSkinName() and ZD_SetMarineSkin() when it comes to retrieving a corresponding skin name from an index, as well as setting a skin based off of the retrieved name.