Open a form and set properties where the form name is stored as a variable

I have 4 forms.   3 of the forms display information. They are called: Form_Info_A,  Form_Info_B,  Form_Info_C

The fourth form is used to select which of the other 3 is opened.  It is called:   Form_Select

On "Form_Select" I have a TextBox control named "MySelection" in which the user will enter the name of one of the three information forms.

On "Form_Select" I also have a Command Button named "cmdPrint" that will:
1) Open the selected form (A, B or C)
2) Change some properties of the selected form
3) Print the selected form
4) Close the selected form

In the OnClick event procedure behind the Command Button I can Open, Print and Close the selected form using a variable which contains the name of the selected form as follows:

'****************************************
Dim stDocName as String
stDocName = Me.MySelection
DoCmd.OpenForm stDocName, acNormal

' ... I need to "SET PROPERTIES" code here

DoCmd.PrintOut
DoCmd.Close
'****************************************

MY PROBLEM is that I want to set some of the properties of the chosen form before it is printed (eg Width, Height, etc) For example I want to change the color of one of the controls named "MyControl".   If I HARDCODE the name of the selected form, and place the following code between the OPEN and PRINT commands then the properties can be set:

Forms!Form_Info_B!MyControl.BackColor = 0

This code works

HOWEVER, I do not want to hardcode one of the form names, I want to use the variable that contains the selected name.

I have tried the following but IT DOES NOT WORK

Forms!STDOCNAME!MyControl.BackColor = 0

Can somebody please tel me how to set the properties using the variable as the form name?

Thank You